The Impact of Anti-Müllerian Hormone on Pregnancy Loss in Fresh and Frozen-thawed Embryo Transfer Cycles: A Retrospective Cohort Study

The Impact of Anti-Müllerian Hormone on Pregnancy Loss in Fresh and Frozen-thawed Embryo Transfer Cycles: A Retrospective Cohort Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The Impact of Anti-Müllerian Hormone on Pregnancy Loss in Fresh and Frozen-thawed Embryo Transfer Cycles: A Retrospective Cohort Study Mingmei Lin, Shan Li, Zeyang Lin, Ruiqi Wang, Zhonghong Zeng, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8159682/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Anti-Müllerian hormone (AMH) is a key biomarker of ovarian reserve in assisted reproductive technology (ART). However, its association with miscarriage risk following embryo transfer remains controversial. This study aims to investigate the correlation between pre-pregnancy serum AMH levels and the risk of miscarriage in patients undergoing in vitro fertilization (IVF). Methods This retrospective cohort study analyzed 10,260 fresh and frozen-thawed embryo transfer cycles resulting in singleton clinical pregnancies at Peking University Third Hospital Reproductive Center during January 2017 to December 2020. Patients were categorized into low AMH (< 1.00 ng/mL) and normal AMH (≥ 1.00 ng/mL) groups. Miscarriage rates were compared, and binary logistic regression was employed to assess the association between AMH levels and spontaneous miscarriage. Results In the fresh embryo transfer cohort (n = 4,982), the low AMH group had significantly higher overall miscarriage (26.0% vs. 19.2%, P < 0.001) and early miscarriage rates (21.9% vs. 15.6%, P < 0.001) than the normal AMH group. This association was prominent in women under 35, who demonstrated higher miscarriage (20.8% vs. 15.4%, P = 0.003) and early miscarriage rates (17.4% vs. 12.5%, P = 0.003). After adjusting for confounders, low AMH remained an independent risk factor for miscarriage in women under the age of 35 (OR = 1.33, 95% CI = 1.02–1.73, P = 0.036). No significant association was found in women ≥ 35. In the frozen-thawed transfer cohort (n = 5,278), the miscarriage rate (23.0% vs. 18.5%, P = 0.018) and early miscarriage rate (20.2% vs. 15.9%, P = 0.020) were significantly higher in the low AMH group. However, stratified analysis by age showed no significant association between AMH levels and any miscarriage outcome (all had P > 0.05). Conclusion Low serum AMH is an independent risk factor for miscarriage after fresh embryo transfer in women under 35, but not in women ≥ 35. For frozen-thawed embryo transfer, AMH levels are not associated with miscarriage risk, regardless of age. Clinical trial number: not applicable. Anti - Müllerian Hormone Embryo Transfer Miscarriage Figures Figure 1 Introduction With the continuous development of assisted reproductive technologies and the growing proportion of women of advanced maternal age, adverse pregnancy outcomes following in vitro fertilization (IVF) and embryo transfer have become a growing concern. Studies have shown that an increase in maternal age is associated with a decline in fertility and a higher risk of miscarriage[ 1 – 3 ]. Miscarriage can harm women's physical health and impose psychological and financial burdens, especially for those undergoing assisted reproduction. Consequently, timely assessment of miscarriage risk and appropriate interventions are vital for these patients. Anti-Müllerian hormone (AMH), produced by ovarian granulosa cells, plays a pivotal role in folliculogenesis[ 4 – 6 ]. Ovarian reserve, which encompasses the quantity and quality of follicles in the ovarian pool, diminishes with advancing age[ 7 – 9 ]. Serum AMH levels serve as an accurate marker of growing follicle count and are considered a reliable indicator of ovarian reserve and response[ 10 – 12 ]. Consequently, AMH measurement has become a routine assessment in the field of assisted reproduction. Nevertheless, the extent to which AMH correlates with oocyte and embryo quality, as well as its potential influence on pregnancy outcomes, particularly miscarriage, remains to be fully elucidated. Current studies on the correlation between serum AMH levels and miscarriage risk have conflicting conclusions. Some studies indicate that pre-pregnancy low AMH levels are linked to higher miscarriage risk. A systematic review and meta - analysis of 13 retrospective studies (N = 12,042) shows that, compared to women with normal or high AMH levels, those with low AMH have a significantly increased miscarriage risk after assisted reproduction ( P = 0.004, OR = 1.35, 95% CI = 1.10–1.66) [13] . A 2017 cohort study with 1,060 patients found that after adjusting for age and oocyte number, low baseline serum AMH raises the risk of early miscarriage after fresh embryo transfer ( P = 0.021)[ 14 ], a prospective study on natural conception found that compared to women with normal AMH (≥ 1.0 ng/mL), those with severe ovarian reserve decline (AMH ≤ 0.4 ng/mL) have a higher miscarriage risk (HR = 2.3, CI = 1.3–4.3)[ 15 ]. However, other studies suggest high AMH levels may also be an independent miscarriage risk factor, possibly due to endocrine changes, similar to those in polycystic ovary syndrome (PCOS). A domestic retrospective study found that in young women, high pre-pregnancy AMH levels (> 3.99 ng/mL) increase early miscarriage risk after fresh embryo transfer, and this was consistent in the non - PCOS subgroup[ 16 ]. Additionally, a prospective study on patients with natural conception showed that both low (AMH 4.5 ng/mL) serum AMH levels during pregnancy are independent risk factors for early natural miscarriage (both P < 0.05)[ 17 ]. In conclusion, despite extensive research on AMH and miscarriage risk, the clinical predictive value of AMH remains controversial, due to inconsistent findings. Moreover, existing studies have some limitations. On the one hand, the predictive ability of AMH may be affected by age, the type of conception (natural conception and assisted reproductive technology), the cause of miscarriage (embryo-origin and maternal-origin) and so on, while some studies fail to conduct stratified analyses of the study population. On the other hand, some studies inadequately control for confounding factors. For example, certain studies may include PCOS patients so that the association between their high AMH levels and miscarriage might be mediated by obesity and metabolic disorders rather than AMH itself. Given that, the retrospective cohort study included the patients from our hospital who underwent IVF and achieved clinical pregnancy. By analyzing pre - pregnancy serum AMH levels, it explores the link between the levels of AMH and miscarriage risk following embryo transfer across different age groups and different types of embryo transfer. The study aims to illuminate the impact of diminished ovarian reserve on assisted reproductive outcomes. It seeks to supply robust evidence for pre - treatment evaluation and pregnancy management in assisted reproductive patients and to advance the clinical application of serum AMH levels. Methods Ethics approval The study was approved by the Ethics Committee of Peking University Third Hospital Reproductive Center (2022-580-01) and adhered to the principle of the Declaration of Helsinki. As the study involved retrospective data analysis without personally identifiable information, the requirement for informed consent was waived. (Clinical trial number: not applicable.) Study design The retrospective cohort study was conducted at Peking University Third Hospital Reproductive Center from January 1, 2017, to December 31, 2020. The study consisted of patients who underwent IVF/ICSI and achieved singleton clinical pregnancies through fresh or frozen-thawed embryo transfer. For each patient, only their first clinical pregnancy within the study period was included in the analysis to evaluate miscarriage outcomes. The process for selecting participants is shown in Figure 1 . Selection and description of the participants The study included participants who met the following criteria: (1)Aged 20 - 45 years; (2)Serum AMH levels measured before ovarian stimulation, within 2 years prior to embryo transfer; (3)Singleton clinical pregnancy achieved after transfer of 1 or 2 embryos. Patients presenting any of the following were excluded: (1)Uterine malformations (e.g.: unicornuate, hemiunicornuate, or septate uterus) or intrauterine adhesions; (2)Chromosomal abnormalities in either partner; (3)Autoimmune diseases (e.g.: Sjögren's syndrome, systemic lupus erythematosus, or antiphospholipid syndrome); (3)Recurrent miscarriage (≥2 consecutive natural miscarriages with the same partner); (4)PCOS, diagnosed per the Rotterdam criteria[18]: at least two of oligomenorrhea / amenorrhea, clinical/biochemical hyperandrogenism, or polycystic ovaries on ultrasound, after excluding other hyperandrogenic etiologies; (5)Oocyte donation or in vitro maturation (IVM) cycles; (6)Loss to follow - up of pregnancy outcomes. Research group Based on clinical practice and the data characteristics of this study, this study used the 2019 ACOG criteria[19], defining AMH <1.00 ng/mL as low. Participants were categorized into two groups: low AMH (AMH <1.00 ng/mL) and normal AMH (AMH ≥1.00 ng/mL), according to their serum AMH levels measured before ovarian stimulation. Protocol All participants underwent controlled ovarian hyperstimulation (COH) following the center's standard protocol. Clinicians selected COH protocols and drug doses by considering patients' age, AFC, AMH levels, basal sex hormone levels, prior IVF retrieved oocytes yield. The primary COH protocols included the GnRH - a long protocol, the ultralong protocol, the short protocol, or the GnRH antagonist protocol. Less than 5% of participants used non- traditional COH protocols, such as mild stimulation protocol, natural cycle protocol, or luteal phase stimulation protocol. (1) GnRH - a long protocol: GnRH - a is administered on day 2 of the menstrual cycle or in the luteal phase. After 14 - 21 days, once pituitary down - regulation is achieved (LH <5~10 IU/L, E2 <50 pg/mL, endometrium <4~5 mm, no functional ovarian cysts), exogenous Gn is started, and GnRH - a continues. (2) GnRH - a ultralong protocol: Long - acting GnRH - a is given on day 2 of the menstrual cycle, repeated after 28 days, and Gn is started 14 days later based on FSH, LH, E2, follicle size and number. (3) GnRH - a short protocol: Short - acting GnRH - a is administered on day 2 of the menstrual cycle, and Gn is started on day 3. (4) Antagonist protocol: Gn is administered daily starting on day 2 or 3 of the menstrual cycle. After 6 days or when at least one follicle reaches 12 mm in diameter, GnRH - antagonist is added. The starting dose of Gn was determined by the patient's age, AFC, basal FSH, and body surface area, usually 112.5 - 300 IU/day. After 4 - 5 days, ultrasound and hormone tests monitored follicle growth, and Gn dosage was adjusted When at least two follicles reached ≥18 mm, hCG was administered, and oocyte retrieval followed 34 - 38 hours later. Fertilization was via IVF or ICSI based on sperm quality or the need for pre - implantation genetic testing. Embryo transfer and follow-up Patients planned for fresh embryo transfer received luteal support beginning on the oocyte retrieval day. In our center, D3 embryos with ≥4 cells and ≤30% fragmentation were regarded as viable for transfer, and blastocysts meeting the Gardner standard (≥4BC or 4CB) were eligible for transfer. All patients underwent blood β-hCG testing 14 days after embryo transfer, with a level >25 IU/L suggesting a chemical pregnancy. Vaginal ultrasound was conducted 30 - 40 days post - transfer to check for gestational sac and fetal heartbeat, confirming clinical pregnancy. Pregnancy outcomes were monitored through telephone follow - up. Data Collection Baseline clinical data, basal hormone levels (including serum AMH), COH protocols, drug doses, details of embryo transfer, and pregnancy outcomes were collected for all participants. All clinical pregnancy cohort data were obtained from the Reproductive Center's clinical database. Outcome measures The study's outcome measures were as follows: Miscarriage was defined as pregnancy termination before 28 weeks' gestation or delivery of a fetus weighing <1000 g. Early miscarriage was pregnancy termination before 12 weeks' gestation. Late miscarriage was pregnancy termination at or after 12 weeks' gestation. The primary outcome was the miscarriage rate, calculated as: (1) Miscarriage rate=Number of miscarriages/Total clinical pregnancies×100% Secondary outcomes were the early and late miscarriage rates, calculated as: Early miscarriage rate=Number of early miscarriages/Total clinical pregnancies ×100% Late miscarriage rate=Number of late miscarriages/Total clinical pregnancies ×100% Statistical analysis All the statistical data were analyzed by using the SPSS 25.0 software (SPSS, Inc, Chicago, IL, USA). For continuous variables, data adhering to a normal distribution were reported as mean ± standard deviation (SD), and those without as median (interquartile range). Categorical variables were expressed as frequencies (percentages). Shapiro-Wilk tests assessed normality, and Levene's tests checked the homogeneity of variances for continuous data across groups. Skewness and kurtosis were additionally evaluated for normality assessment when Shapiro-Wilk results were borderline (absolute values >2 considered non-normal). Groups with continuous data meeting homogeneity and normality were compared using independent samples t-tests; non-parametric tests were used otherwise. Categorical variables were analyzed using Pearson's chi-squared test or Fisher's exact test, as appropriate. Binary logistic regression adjusted for a priori confounders (age, infertility duration) and clinically relevant variables identified in univariate analyses: COS protocols, Gn dosage, ICSI fertilization, and embryo transfer characteristics The Hosmer-Lemeshow test was used to evaluate the regression models' fit. Statistical significance was set at a two-sided P value＜0.05. Results Our analysis included 10,260 embryo transfer cycles from Peking University Third Hospital, between January 2017 and December 2020, after applying the inclusion and exclusion criteria (Fig. 1 ). Of the included cycles, 4,982 were fresh embryo transfers (48.56%) and 5,278 were frozen - thawed embryo transfers (51.44%). Baseline characteristics, relevant IVF data and pregnancy outcomes of patients following fresh or frozen-thawed embryo transfer The baseline characteristics and pregnancy outcomes of patients undergoing fresh or frozen - thawed embryo transfer are summarized in Table 1 and Table 2 . Among 10,260 eligible cycles, 4,982 (48.6%) were fresh embryo transfers (FET) and 5,278 (51.4%) frozen-thawed embryo transfers (FET). Table 1 Baseline characteristics, relevant IVF-ET data and pregnancy outcomes of patients Characteristics Group 1 ‡ (N = 1017) Group 2 ‡ (N = 3965) χ 2 /Z value P value Age, median (IQR * ), year 35.00 (31.00, 37.50) 32.00 (29.00, 35.00) 14.59 <0.001 BMI * , median (IQR), kg/m 2 22.07 (20.23, 24.60) 21.90 (20.10, 24.20) 2.42 0.016 Primary Infertility, percentage (No./N) 54.6 (555/1017) 58.9 (2336/3965) 6.09 0.014 Infertile duration, median (IQR) 3 (2, 6) 3 (2, 5) 3.65 <0.001 No. of parity, median (IQR), times 0 (0, 1) 0 (0, 1) 2.48 0.013 No. of gravidity, median (IQR), times 0 (0, 0) 0 (0, 0) 1.18 0.24 FSH * , median (IQR), (U/L) 7.81 (5.98, 10.10) 6.51 (5.24, 7.90) 12.78 <0.001 No. of AFC * , median (IQR) 6 (4, 7) 10 (7, 13) -28.63 <0.001 Fallopian tube factors, percentage (No./N) 32.1 (326/1017) 39.6 (1570/3965) 19.21 <0.001 Endometriosis, percentage (No./N) 12.0 (122/1017) 8.5 (339/3965) 11.04 0.001 Male factors, percentage (No./N) 49.1 (499/1017) 54.3 (2153/3965) 8.7 0.003 Thyroid disease, percentage (No./N) 1.9 (19/1017) 2.1 (83/3965) 0.9 0.343 Uterine Fibroid, percentage (No./N) 10.5 (107/1017) 6.9 (275/3965) 14.7 <0.001 Failure of IVF * , percentage (No./N) 30.5 (310/1017) 19.9 (788/3965) 52.39 <0.001 Protocol of COS * , percentage (No./N) 132.88 <0.001 Ultralong protocol 11.8 (120/1017) 16.9 (671/3965) Long GnRH * agonist 23.5 (239/1017) 29.4 (1166/3965) GnRH agonist 57.0 (580/1017) 52.1 (2065/3965) Others † 7.7 (78/1017) 1.6 (63/1017) Gn * dosage, median (IQR), U 3425 (2606, 4350) 2575 (1950, 3375) 17.84 <0.001 Gn duration, median (IQR), day 11 (9, 13) 11 (10, 13) -2.06 0.039 ICSI * , percentage (No./N) 28.4 (289/1017) 38.2 (1514/3965) 33.44 <0.001 Cleavage stage embryo, percentage (No./N) 24.4 (248/1017) 13.7 (543/3965) 68.46 <0.001 Blastocysts, percentage (No./N) 3.2 (33/1017) 6.3 (250/3965) 13.89 <0.001 Miscarriage, percentage (No./N) 26.0 (264/1017) 19.2 (760/3965) 22.45 <0.001 Early Miscarriage, percentage (No./N) 21.9 (223/1017) 15.6 (618/3965) 22.74 <0.001 Late Miscarriage, percentage (No./N) 4.0 (41/1017) 3.6 (141/3965) 0.393 0.531 * Abbreviations: IQR, interquartile range; BMI, body mass index; FSH, follicle-stimulating hormone; AFC, antral follicle counting; IVF, in vitro fertilization; COS, controlled ovarian stimulation; GnRH, gonadotropin-releasing hormone; Gn, gonadotropin; ICSI, intracytoplasmic sperm injection † Others include the short protocol, the micro-stimulation protocol and the luteal-phase ovulation induction protocol ‡ Group 1: women with low level of AMH (<1.00 ng/ml) and following fresh embryo transfer Group 2: women with normal level of AMH (≥ 1.00 ng/ml) and following fresh embryo transfer Table 2 Baseline characteristics, relevant IVF-FET data and pregnancy outcomes of patients Characteristics Group 3 ‡ (N = 486) Group 4 ‡ (N = 4792) χ 2 /Z value P value Age, median (IQR * ), year 34.00 (31.00, 37.00) 32.00 (29.00, 35.00) 11.34 <0.001 BMI * , median (IQR), kg/m 2 21.80 (20.10, 24.40) 21.60 (19.80, 23.90) 2.23 0.026 Primary Infertility, percentage (No./N) 58.2 (283/486) 61.4 (2941/4792) 1.88 0.17 Infertile duration, median (IQR) 3 (2, 6) 3 (2, 5) 2.54 0.011 No. of parity, median (IQR), times 0 (0, 1) 0 (0, 1) 0.09 0.929 No. of gravidity, median (IQR), times 0 (0, 0) 0 (0, 0) 0.83 0.408 FSH * , median (IQR), (U/L) 7.51 (5.82, 9.67) 6.22 (5.04, 7.42) 10.23 <0.001 No. of AFC * , median (IQR) 6 (4, 9) 11 (8, 14) 21.93 <0.001 Fallopian tube factors, percentage (No./N) 36.8 (179/486) 44.5 (2134/4792) 10.32 0.001 Endometriosis, percentage (No./N) 14.0 (68/486) 8.1 (389/4792) 18.52 <0.001 Male factors, percentage (No./N) 52.5 (255/486) 58.9 (2823/4792) 7.27 0.007 Thyroid disease, percentage (No./N) 1.9 (9/486) 2.0 (96/4792) 0.05 0.82 Uterine Fibroid, percentage (No./N) 8.4 (41/486) 6.4 (307/4792) 2.95 0.086 Failure of IVF * , percentage (No./N) 30.7 (149/486) 17.3 (830/4792) 51.08 <0.001 Protocol of COS * , percentage (No./N) 105.35 <0.001 Ultralong protocol 6.8 (33/486) 11.9 (568/4792) Long GnRH * agonist, 21.6 (105/486) 28.1 (1347/4792) GnRH agonist 64.0 (311/486) 58.6 (2810/4792) Others † 7.6 (37/486) 1.4 (67/4792) Gn * dosage, median (IQR), U 3150 (2475, 3881) 2250 (1662.5, 3000) 14.92 <0.001 Gn duration, median (IQR), day 11 (9, 12) 11 (10, 12) -2.25 0.025 Protocol of Endometrial Preparation, percentage (No./N) 3.65 0.161 Natural cycle 61.7 (300/486) 57.6 (2759/4792) Artificial cycle 28.5 (139/486) 30.5 (1460/4792) Ovarian stimulation cycle 9.5 (46/486) 11.6 (558/4792) ICSI * , percentage (No./N) 28.8 (140/486) 43.7 (2091/4792) 39.76 <0.001 Cleavage stage embryo, percentage (No./N) 73.3 (356/486) 66.3 (3179/4792) 5.89 0.015 Blastocysts, percentage (No./N) 72.8 (354/486) 66.5 (3188/4792) 7.62 0.006 Miscarriage, percentage (No./N) 23.0 (112/486) 18.5 (887/4792) 5.62 0.018 Early Miscarriage, percentage (No./N) 20.2 (98/486) 15.9 (764/4792) 5.45 0.020 Late Miscarriage, percentage (No./N) 2.9 (14/486) 2.5 (122/4792) 0.09 0.769 * Abbreviations: IQR, interquartile range; BMI, body mass index; FSH, follicle-stimulating hormone; AFC, antral follicle counting; IVF, in vitro fertilization; COS, controlled ovarian stimulation; GnRH, gonadotropin-releasing hormone; Gn, gonadotropin; ICSI, intracytoplasmic sperm injection † Others include the short protocol, the micro-stimulation protocol and the luteal-phase ovulation induction protocol ‡ Group 3: women with low level of AMH (<1.00 ng/ml) and following frozen-thawed embryo transfer Group 4: women with normal level of AMH (≥ 1.00 ng/ml) and following frozen-thawed embryo transfer Significant baseline differences existed between AMH groups (Table 1 ) in fresh embryo transfer cycles: The low AMH group (< 1.00 ng/mL) was older (median 35 vs. 32 years, P < 0.001), had higher FSH (7.81 vs. 6.51 IU/L, P < 0.001), and lower AFC (6 vs. 10, P < 0.001). Notably, the low AMH group had higher rates of endometriosis (12.0% vs. 8.5%, P = 0.001) and prior IVF failure (30.5% vs. 19.9%, P < 0.001), suggesting residual confounding despite stratification. In IVF - related parameters, the low AMH group used more Gn (Z = 17.84, P < 0.001) but for a shorter time (Z=-2.06, P = 0.039), had a lower ICSI rate (χ²=33.44, P < 0.001), and a higher cleavage stage embryo or blastocyst transfer rate (χ²=68.46 and 13.89, both P < 0.001). Regarding pregnancy outcomes, the low AMH group had higher miscarriage and early miscarriage rates (χ²=22.45 and 22.74, both P < 0.001), with no significant difference in late miscarriage rates (χ²=0.393, P = 0.531). As shown in Table 2 , in frozen - thawed embryo transfer cycles, the low AMH group (N = 486) had higher age (Z = 11.34, P < 0.001), longer infertility duration (Z = 2.54, P = 0.011), higher BMI (Z = 2.23, P = 0.026) and a slightly lower rate of primary infertility (χ² = 1.88, P = 0.170) than the normal AMH group (N = 4,792). Basal FSH was higher (Z = 10.23, P < 0.001) and AFC was lower (Z = -21.93, P < 0.001) in the low AMH group. In terms of infertility causes, the low AMH group had fewer tubal - factor cases (χ² = 10.32, P = 0.001) but more endometriosis cases (χ² = 18.52, P < 0.001), with no significant difference in uterine - fibroid cases (χ² = 2.95, P = 0.086). Prior IVF failure was more common in the low AMH group (χ² = 51.08, P < 0.001). There were also differences in protocols of COS (χ²=105.35, P < 0.001), with the low AMH group using more Gn (Z = 14.92, P < 0.001) but for a shorter time (Z=-2.25, P = 0.025). The low AMH group had a lower ICSI rate (χ²=39.76, P < 0.001) and higher rates of cleavage stage embryo (χ²=5.89, P = 0.015) and blastocyst transfer (χ²=7.62, P = 0.006). In pregnancy outcomes, the low AMH group had higher miscarriage (χ²=5.62, P = 0.018) and early miscarriage rates (χ²=5.45, P = 0.020), with no significant difference in late miscarriage rates (χ²=0.09, P = 0.769). Comparison of fresh embryo transfer pregnancy outcomes in women aged <35 and ≥ 35 with Different AMH Levels The study showed that in both fresh and frozen - thawed embryo transfer cycles, the low AMH group exhibited higher miscarriage and early miscarriage rates than the normal AMH group. However, significant differences in baseline characteristics and IVF related data were found between the different AMH groups across these cycles. To better analyze how AMH levels relate to pregnancy outcomes, it is necessary to better match the differences between groups. Patients were stratified into two age subgroups (≥ 35 and < 35 years) to account for differences in baseline data and IVF treatment processes. Tables 3 and 4 provide detailed results of the comparisons within these subgroups. Table 3 Binary logistic regression analysis of pregnancy outcomes of fresh embryo transfer in IVF cycles Outcomes Aged ≥ 35 Aged < 35 OR * (95%CI * ) P value † OR (95%CI) P value Miscarriage 1.03 (0.79 ~ 1.32) 0.85 1.33 (1.02 ~ 1.73) 0.036 Early Miscarriage 1.04 (0.79 ~ 1.36) 0.788 1.38 (1.04 ~ 1.83) 0.028 Late Miscarriage 0.96 (0.56 ~ 1.65) 0.887 1.09 (0.61 ~ 1.98) 0.768 * Abbreviations: OR, odds ratio; CI, confidence intervals; LH, luteinizing hormone; Gn, gonadotropin; E2, estradiol. † Adjusted for age, BMI, infertile factor, Gn dosage, protocol of COS, ICSI, type of embryos transferred, number of embryos transferred. The model was tested by Hosmer-Lemeshow. Table 4 Binary logistic regression analysis of pregnancy outcomes of frozen-thawed embryo transfer in IVF cycles Outcomes Aged ≥ 35 Aged < 35 OR * (95%CI * ) P value † OR (95%CI) P value Miscarriage 0.95(0.66 ~ 1.39) 0.802 1.06 (0.76 ~ 1.50) 0.727 Early Miscarriage 0.99 (0.67 ~ 1.48) 0.977 1.05(0.75 ~ 1.50) 0.788 Late Miscarriage 0.78 (0.30 ~ 2.03) 0.613 1.10 (0.48 ~ 2.53) 0.828 * Abbreviations: OR, odds ratio; CI, confidence intervals; LH, luteinizing hormone; Gn, gonadotropin; E2, estradiol. † Adjusted for age, BMI, infertile factor, Gn dosage, protocol of COS, ICSI, type of embryos transferred, number of embryos transferred. The model was tested by Hosmer-Lemeshow. As indicated in Supplementary table 1 , among patients who were 35 years or older and achieved clinical pregnancies following fresh embryo transfer, there were 518 in the low AMH group and 1,149 in the normal AMH group. In terms of baseline data, the low AMH group had a significantly higher age (Z = 4.20, P < 0.001) but comparable BMI (P = 0.995). The low AMH group also exhibited higher basal FSH (Z = 8.59, P < 0.001) and lower AFC (Z = -17.13, P < 0.001). They had a lower proportion of tubal factors (χ² = 12.87, P < 0.001). IVF failure was more common in the low AMH group (χ² = 11.91, P = 0.001). Additionally, the low AMH group used more Gn (Z = 6.11, P < 0.001) but for a shorter duration (Z = -2.46, P = 0.014), had a lower ICSI rate (χ² = 4.80, P = 0.028), and a higher rate of cleavage stage embryo (χ² = 34.15, P < 0.001) and blastocyst transfer (χ² = 5.68, P = 0.017). Regarding pregnancy outcomes, the miscarriage rate was 30.9% in the low AMH group and 28.5% in the normal AMH group, with no significant difference (χ² = 0.90, P = 0.342). Similarly, no significant differences were found in early (26.3% vs. 23.2%, χ² = 1.71, P = 0.190) and late miscarriage rates (4.6% vs. 5.3%, χ² = 0.21, P = 0.645). Supplementary table 2 shows that among patients under 35 with clinical pregnancies from fresh embryo transfer, 499 were in the low AMH group and 2,816 in the normal AMH group. The low AMH group had higher age (Z = 5.88, P < 0.001), slightly higher BMI (Z = 2.21, P = 0.027), and longer infertility duration (Z = 2.75, P = 0.006). They also had higher basal FSH (Z = 8.39, P < 0.001), lower AFC (Z = -20.51, P < 0.001), and a higher proportion of endometriosis (χ² = 20.83, P < 0.001). IVF failure was more common in the low AMH group (χ² = 16.05, P < 0.001). The low AMH group used more Gn (Z = 15.47, P < 0.001), had a lower ICSI rate (χ² = 17.92, P < 0.001), and a higher rate of cleavage stage embryo (χ² = 20.11, P < 0.001) and blastocyst transfer (χ² = 7.10, P = 0.008). In pregnancy outcomes, the miscarriage rate was significantly higher in the low AMH group (20.8% vs. 15.4%, χ² = 8.93, P = 0.003), as was the early miscarriage rate (17.4% vs. 12.5%, χ² = 8.56, P = 0.003). No significant difference was found in late miscarriage rates (3.4% vs. 2.8%, χ² = 0.30, P = 0.584), suggesting AMH’s effect may be limited to early pregnancy loss. These results indicate that in patients under 35, low AMH levels are significantly associated with a higher risk of miscarriage following fresh embryo transfer, particularly in the case of early miscarriage. Comparison of frozen-thawed embryo transfer pregnancy outcomes in women aged ≥ 35 and <35 with Different AMH Levels Among the clinical pregnancies from frozen - thawed embryo transfer, there were 486 in the low AMH group and 4,792 in the normal AMH group. Subgroup analysis was performed based on age (≥ 35 years and < 35 years), and the results of the comparison between the two groups are presented in Supplementary Tables 3 and 4. As shown in Supplementary table 3, among women aged 35 and older with clinical pregnancies from frozen - thawed embryo transfer, there were 229 in the low AMH group and 1,263 in the normal AMH group. The low AMH group had significantly higher age (Z = 4.91, P < 0.001), higher basal FSH (Z = 6.93, P < 0.001), and lower AFC (Z = -12.57, P < 0.001). They also had a lower rate of tubal factors (χ² = 4.73, P = 0.030) but a higher rate of endometriosis (χ² = 6.71, P = 0.010). IVF failure was more common in the low AMH group (χ² = 9.28, P = 0.002). The low AMH group used more Gn (Z = 5.89, P < 0.001) but for a shorter duration (Z = -2.56, P = 0.010), had a lower ICSI rate (χ² = 18.28, P < 0.001), and a higher rate of cleavage stage embryo (χ² = 5.77, P = 0.016) and blastocyst transfer (χ² = 7.32, P = 0.007). The differences in BMI (P = 0.707), primary infertility rate (P = 0.442), and infertility duration (P = 0.486) between the two groups were not statistically significant. Among women aged ≥ 35 years, there was a higher miscarriage rate in the low AMH group (30.6%) compared to the normal AMH group (26.4%), but the difference was not statistically significant (χ² = 1.47, P = 0.226). Similarly, no significant differences were found in early miscarriage rates (27.1% vs. 23.1%, P = 0.226) or late miscarriage rates (3.5% vs. 3.3%, P = 1.000). As shown in Supplementary table 4, among women under the age of 35, there were 257 patients in the low AMH group and 3,529 in the normal AMH group. The low AMH group demonstrated significantly higher age (Z = 5.43, P < 0.001), significantly higher basal FSH levels (Z = 6.86, P < 0.001), and significantly lower AFC (Z = -16.76, P < 0.001). Additionally, the low AMH group had a higher proportion of endometriosis cases (χ² = 11.09, P = 0.001), used a higher dosage of Gn (Z = 12.55, P < 0.001), and had a lower ICSI rate (χ² = 16.35, P < 0.001). However, differences in infertility duration (P = 0.669), cleavage stage embryo transfer rate (P = 0.170), and blastocyst transfer rate (P = 0.426) between the two groups were not statistically significant. In terms of pregnancy outcomes, the low AMH group had a miscarriage rate of 16.3% compared to 15.7% in the normal AMH group (χ² = 0.04, P = 0.844). Similarly, no significant differences were found in early miscarriage rates (14.0% vs. 13.4%, P = 0.847) or late miscarriage rates (2.3% vs. 2.3%, P = 1.000). Binary logistic regression analysis of pregnancy outcomes Further binary logistic regression analyses were performed for women aged ≥ 35 years and < 35 years. Variables included the miscarriage, early miscarriage and late miscarriage; and covariates like age, BMI, and variables with significant differences ( P < 0.05) in baseline data and IVF treatment between AMH groups. As shown in Table 3 , in fresh embryo transfer cycles, after controlling for confounding factors, low AMH levels were not significantly associated with miscarriage risk in women aged ≥ 35 (OR = 1.03, 95% CI = 0.79–1.32, P = 0.850). However, in women under 35, low AMH levels were significantly associated with miscarriage risk (OR = 1.33, 95% CI = 1.02–1.73, P = 0.036), particularly early miscarriage (OR = 1.38, 95% CI = 1.04–1.83, P = 0.028), while with no significant association with late miscarriage (OR = 1.09, 95% CI = 0.61–1.98, P = 0.768). As shown in Table 4 , in frozen - thawed embryo transfer cycles, after adjusting for confounding factors, low AMH levels were not significantly associated with miscarriage risk in women aged ≥ 35 years (OR = 0.95, 95% CI = 0.66–1.39, P = 0.802). Similarly, in women under 35, low AMH levels were not significantly associated with miscarriage risk (OR = 1.06, 95% CI = 0.76–1.50, P = 0.727), nor with early or late miscarriage risk (P = 0.788 and P = 0.828). Binary logistic regression adjusted for age, BMI, COS protocol, and embryo transfer parameters confirmed low AMH as an independent risk factor for miscarriage in women < 35 after fresh ET (adjusted-OR = 1.33, P = 0.036), but not in FET cycles or older women (Table 3 – 4 ). Notably, Gn dosage and endometriosis status did not fully explain this association (Hosmer - Lemeshow P > 0.05 for all models). Discussion The study analyzed 10,260 clinical pregnancies from embryo transfer, including 4,982 fresh and 5,278 frozen - thawed embryo transfer cycles, using serum AMH levels of 1.00 ng/mL as the classification threshold. Results showed that low AMH was linked to higher miscarriage risk in both fresh and frozen - thawed cycles. Subgroup analysis indicated this was significant only in women under 35 following fresh embryo transfer. Binary logistic regression revealed that low AMH was an independent risk factor for miscarriage and early miscarriage in fresh cycles for women under 35, even after adjusting for potential confounders. However, no significant association was found between AMH levels and miscarriage risk in women aged ≥ 35 following fresh embryo transfer or those following frozen-thawed embryo transfer. Our findings suggest a correlation between serum AMH levels and the risk of early miscarriage following fresh embryo transfer, which varies with patient age. Advanced maternal age is the primary factor for early miscarriage in older patients. Conversely, in younger patients, low AMH levels (< 1.00 ng/mL) emerge as an independent risk factor for miscarriage. These results highlight the potential of AMH as a predictive biomarker for miscarriage risk in young women undergoing fresh embryo transfer, suggesting that pre-treatment AMH screening could guide personalized clinical interventions, such as intensified luteal support or preimplantation genetic testing, to mitigate early pregnancy loss. Some previous studies align with parts of our findings. Tarasconi et al.[ 14 ] analyzed 1,060 fresh - embryo transfer pregnancies and found low AMH (AMH 33. Our age-stratified analysis contradicts this. This discrepancy may stem from different AMH thresholds (1.6 ng/mL in their study vs. 1.0 ng/mL in ours per ACOG guidelines), which can affect risk stratification. Moreover, in the study, even within age groups, significant age differences between AMH groups may confound results. Notably, Hong et al.[ 20 ]studied 848 infertile women, 206 of whom had early miscarriages. They found both age and serum AMH independently associated with early miscarriage ( P = 0.022). Other studies suggest no link between AMH levels and miscarriage. Zhang et al.'s[ 21 ] large retrospective study of 9,431 first - time IVF patients found no independent correlation between AMH levels (using the 25th and 75th percentiles as cutoffs) and miscarriage rates after fresh embryo transfer. Discrepancies between this study and ours may arise from different AMH cutoffs and the inclusion of PCOS patients or other disease - related factors in their study that could impact results. Although our study shows low AMH is associated with miscarriage in women under 35 after fresh embryo transfer, the underlying mechanism is unclear. This may relate to several hypotheses combining AMH's physiological role and clinical application. Firstly, it might be associated with decreased oocyte quality. AMH, a key regulator secreted by granulosa cells in small follicles, reflects ovarian reserve depletion. Its reduction may indirectly impair oocyte maturation. Specific factors secreted by oocytes, such as GDF − 9 and BMP15, can act on granulosa cells and downregulate AMH expression[ 22 ]. Aged ≥ 37 show downregulated TGF - β-related protein expression (including AMH) in cumulus cells, which affects follicle development and oocyte maturation[ 23 ]. AMH levels in young women may reduce oocyte quality and increase miscarriage risk. Notably, oocyte aging in women ≥ 35 may mask the impact of AMH, while young women with rapid ovarian reserve depletion are more prone to oocyte quality defects. Second, it might relate to AMH's impact on endometrial receptivity. Evidence shows that endometrial cells express AMH, AMHRⅡ, and molecules in the AMH - pathway like ALK3, Smads1, and Smads9, indicating a functional AMH signaling system in the endometrium[ 24 – 26 ]. However, the exact physiological role and mechanism of AMH are still unclear. Paulson et al.[ 27 ] reported that AMHRⅡ expression in the endometrium varies with the menstrual cycle, and has a substantial increase in the luteal phase. Fu et al.[ 28 ] found that in women with recurrent implantation failure, AMHRⅡ expression in endometrial cells is higher, with downregulated estrogen and prolactin receptors and increased apoptosis in luteal - phase cells. Thus, AMH may affect pregnancy outcomes by binding to AMHRⅡ, inducing apoptosis, and disrupting decidualization. Lastly, ovarian stimulation protocols may play a role. Serum AMH is a reliable predictor of ovarian response and influences the choice of stimulation protocol and drug dose. Our data show that patients with low AMH levels often use the antagonist protocol and higher Gn doses. Our study controlled for the impact of ovarian stimulation protocols using binary logistic regression but did not account for Gn dosage. Wang et al.[ 29 ] reported that in antagonist - protocol patients, the aneuploidy rate in miscarriage tissue and Preimplantation Genetic Testing for Aneuploidy (PGT - A) cycles was higher than in the GnRH - a long protocol group. Further research is needed to confirm the link between Gn dosage and aneuploidy or miscarriage. The study has several strengths over previous research. First, it has the largest sample size to date investigating the link between serum anti-Müllerian hormone (AMH) levels and miscarriage risk, which enhances the credibility of our findings. Second, while prior studies have primarily focused on AMH as an ovarian reserve marker, our study extends this by examining its association with miscarriage risk, further filling a knowledge gap in this field. Moreover, our results have significant implications for clinical practice and policymaking. Our data suggest that young women with low AMH levels should be informed of their increased miscarriage risk during IVF, and clinicians should consider AMH levels when devising individualized treatment plans. However, our study has several limitations. First, even though it has a large sample size, as a retrospective study itself, it might lead to selection bias. This could impact how widely the results can be applied and how reliable they are. Second, the absence of wet lab validation restricts the discussion of biological mechanisms underlying the results. Third, despite adjusting for confounders, residual confounding by unmeasured factors (e.g., embryonic aneuploidy rates) cannot be excluded. Lastly, the study cohort doesn't fully represent different races and ages, which might affect the reproducibility of the findings. Future studies should aim to strengthen the current evidence through prospective, multicenter designs with larger sample sizes. In addition, further research is needed to elucidate the underlying mechanisms through which low AMH levels contribute to an increased risk of miscarriage. It would also be valuable to investigate dynamic changes in AMH levels—such as those occurring before and after ovarian stimulation or during early pregnancy—to determine their potential predictive value for miscarriage. This retrospective study of 10,260 embryo transfer cycles shows that in women under 35, following fresh embryo transfer, low serum AMH (< 1.00 ng/mL) predicts increased miscarriage risk, especially in early pregnancy. It offers new insights into AMH as a biomarker and provides guidance for future clinical practice. Conclusion In conclusion, AMH levels showed no link to miscarriage risk in women over 35 following fresh embryo transfer or those aged 20–45 but following frozen embryo transfer. However, in women under 35 following fresh embryo transfer, low serum AMH (< 1.00 ng/mL) was found to predict higher miscarriage risk, particularly in early pregnancy. Young women with low AMH undergoing fresh embryo transfer may benefit from enhanced luteal support or preimplantation genetic testing. Future research should focus on exploring AMH's clinical potential and its applicability across different populations to improve women's reproductive health management. Abbreviations AMH Anti Müllerian hormone ART Assisted reproductive technology IVF In vitro fertilization IVM In vitro maturation COH Controlled ovarian hyperstimulation AFC Antral follicle counts FSH Follicle-stimulating hormone BMI Body mass index COS Controlled ovarian stimulation GnRH Gonadotropin-releasing hormone Gn Gonadotropin ICSI Intracytoplasmic sperm injection LH Luteinizing hormone E2 Estradiol Declarations Acknowledgements We appreciate the support from the clinical database of Peking University Third Hospital Reproductive Center. Author contributions MML, SL and ZYL took part in designing the study, analyzing data, interpreting data, writing and reviewing the manuscript. RQW, ZHZ and DM interpreted data and reviewed the manuscript. RL was responsible for the study concept, interpreting data,reviewing the manuscript and approving the final version. Funding This study was supported by Clinical Key Incubation Project A of Peking University Third Hospital (BYSYZD2023022), the National Key R&D Program of China (2022YFC2702500, 2021YFC2700601, 2021YFC2700303), Natural Science National Foundation of China (81925013,82288102), the Frontiers Medical Center, Tianfu Jincheng Laboratory Foundation (Project No. TFJC2023010001) and the Key Projects of Yunnan Province Science and Technology Department(202302AA310044). Data availability Data will be made available on request. Ethics approval and consent to participate The study was approved by the Ethics Committee of Peking University Third Hospital Reproductive Center (2022-580-01) and adhered to the principle of the Declaration of Helsinki. As the study involved retrospective data analysis without personally identifiable information, the requirement for informed consent was waived. (Clinical trial number: not applicable.) Competing Interests The authors declare that there is no conflicts of interest. Human ethics and consent to participate declarations Not applicable. References Ezoe K, Miki T, Akaike H, Shimazaki K, Takahashi T, Tanimura Y, et al. Maternal age affects pronuclear and chromatin dynamics, morula compaction and cell polarity, and blastulation of human embryos. Hum Reprod. 2023;38:387–99. Jiang W, Zheng Z, Yan N, Yao S, Xie Q, Ni D, et al. Maternal age-related declines in live birth rate following single euploid embryo transfer: a retrospective cohort study. J Ovarian Res. 2025;18:24. Nguyen DT, Archer H, Earle A, Petyak E, Collins C, Vaillant K, et al. Maternal age is associated with apoptotic gene abundance patterns in blastocoel fluid-conditioned media from euploid embryos: a pilot study. J Assist Reprod Genet. 2025;42:1651–61. Racine C, Genêt C, Bourgneuf C, Dupont C, Plisson-Petit F, Sarry J, et al. New Anti-Müllerian Hormone Target Genes Involved in Granulosa Cell Survival in Women With Polycystic Ovary Syndrome. J Clin Endocrinol Metab. 2021;106:e1271–89. Calcaterra V, Rossi V, Massini G, Casini F, Zuccotti G, Fabiano V. Probiotics and Polycystic Ovary Syndrome: A Perspective for Management in Adolescents with Obesity. Nutrients. 2023, 15. Karaviti E, Karaviti D, Kani ER, Chatziandreou E, Paschou SA, Psaltopoulou T, et al. The role of anti-Müllerian hormone: insights into ovarian reserve, primary ovarian insufficiency, and menopause prediction. Endocrine. 2025;89:338–55. Bleil ME, Gregorich SE, Adler NE, Sternfeld B, Rosen MP, Cedars MI. Race/ethnic disparities in reproductive age: an examination of ovarian reserve estimates across four race/ethnic groups of healthy, regularly cycling women. Fertil Steril. 2014;101:199–207. Hu L, Yang H, Luo H, Zhang Y, Wang X, Wei S, et al. Age-specific reference ranges and variation of anti-mülerian hormone in healthy Chinese women of reproductive and perimenopausal age: a nationwide population-based prospective multicenter cross-sectional study. Gynecol Endocrinol. 2025;41:2431230. Kotlyar AM, Seifer DB. Ethnicity/Race and Age-Specific Variations of Serum AMH in Women-A Review. Front Endocrinol (Lausanne). 2020;11:593216. Wang X, Jin L, Mao YD, Shi JZ, Huang R, Jiang YN, et al. Evaluation of Ovarian Reserve Tests and Age in the Prediction of Poor Ovarian Response to Controlled Ovarian Stimulation-A Real-World Data Analysis of 89,002 Patients. Front Endocrinol (Lausanne). 2021;12:702061. Andreu A, Flores L, Méndez M, Ibarzabal A, Casals G, Mercadé I, et al. Impact of bariatric surgery on ovarian reserve markers and its correlation with nutritional parameters and adipokines. Front Endocrinol (Lausanne). 2024;15:1284576. Zhao J, Zhang S, Chen L, Liu X, Su H, Chen L, et al. Sphingosine 1-phosphate protects against radiation-induced ovarian injury in female rats-impact on mitochondrial-related genes. Reprod Biol Endocrinol. 2020;18:99. Busnelli A, Somigliana E, Cirillo F, Levi-Setti PE. Is diminished ovarian reserve a risk factor for miscarriage? Results of a systematic review and meta-analysis. Hum Reprod Update. 2021;27:973–88. Tarasconi B, Tadros T, Ayoubi JM, Belloc S, de Ziegler D, Fanchin R. Serum antimüllerian hormone levels are independently related to miscarriage rates after in vitro fertilization-embryo transfer. Fertil Steril. 2017;108:518–24. Lyttle Schumacher BM, Jukic AMZ, Steiner AZ. Antimüllerian hormone as a risk factor for miscarriage in naturally conceived pregnancies. Fertil Steril. 2018;109:1065–e10711061. Liu X, Han Y, Wang X, Zhang Y, Du A, Yao R, et al. Serum anti-Müllerian hormone levels are associated with early miscarriage in the IVF/ICSI fresh cycle. BMC Pregnancy Childbirth. 2022;22:279. Kostrzewa M, Żyła M, Garnysz K, Kaczmarek B, Szyłło K, Grzesiak M. Anti-Müllerian hormone as a marker of abortion in the first trimester of spontaneous pregnancy. Int J Gynaecol Obstet. 2020;149:66–70. Abdalla MA, Deshmukh H, Mohammed I, Atkin S, Reid M, Sathyapalan T. The Effect of Free Androgen Index on the Quality of Life of Women With Polycystic Ovary Syndrome: A Cross-Sectional Study. Front Physiol. 2021;12:652559. Infertility Workup for the Women's Health Specialist. ACOG Committee Opinion, Number 781. Obstet Gynecol. 2019;133:e377–84. Hong S, Chang E, Han EJ, Min SG, Kim S, Kang MK, et al. The anti-Mullerian hormone as a predictor of early pregnancy loss in subfertile women. Syst Biol Reprod Med. 2020;66:370–7. Zhang B, Meng Y, Jiang X, Liu C, Zhang H, Cui L, et al. IVF outcomes of women with discrepancies between age and serum anti-Müllerian hormone levels. Reprod Biol Endocrinol. 2019;17:58. Silva MSB, Giacobini P. New insights into anti-Müllerian hormone role in the hypothalamic-pituitary-gonadal axis and neuroendocrine development. Cell Mol Life Sci. 2021;78:1–16. Al-Edani T, Assou S, Ferrières A, Bringer Deutsch S, Gala A, Lecellier CH, et al. Female aging alters expression of human cumulus cells genes that are essential for oocyte quality. Biomed Res Int. 2014;2014:964614. Wang J, Dicken C, Lustbader JW, Tortoriello DV. Evidence for a Müllerian-inhibiting substance autocrine/paracrine system in adult human endometrium. Fertil Steril. 2009;91:1195–203. Mohamed AA, Al-Hussaini TK, Hussein RS, Abdallah KS, Amer SA. The Impact of High Circulating Anti-Müllerian Hormone on Endometrial Thickness and Outcome of Assisted Reproductive Technology in Women with Polycystic Ovarian Syndrome: A Cohort Study. J Hum Reprod Sci. 2022;15:370–6. Tal R, Seifer CM, Khanimov M, Seifer DB, Tal O. High serum Antimullerian hormone levels are associated with lower live birth rates in women with polycystic ovarian syndrome undergoing assisted reproductive technology. Reprod Biol Endocrinol. 2020;18:20. Paulson M, Sahlin L, Hirschberg AL. Endometrial expression of anti-Müllerian hormone and its type II receptor in women with polycystic ovary syndrome. Reprod Biomed Online. 2020;41:128–37. Fu YX, Yang HM, OuYang XE, Hu R, Hu T, Wang FM. Assessment of Anti-Mullerian Hormone and Anti-Mullerian Hormone Type II Receptor Variants in Women with Repeated Implantation Failures. Reprod Sci. 2021;28:406–15. Wang J, Zhang J, Zhao N, Ma Y, Wang X, Gou X, et al. The effect of ovarian stimulation on aneuploidy of early aborted tissues and preimplantation blastocysts: comparison of the GnRH agonist long protocol with the GnRH antagonist protocol. J Assist Reprod Genet. 2022;39:1927–36. Additional Declarations No competing interests reported. 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14:11:11","extension":"html","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":183821,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8159682/v1/02282f36a21be37c662e8845.html"},{"id":98322418,"identity":"33d6c71e-5811-4c66-90e7-4173dc558d58","added_by":"auto","created_at":"2025-12-16 14:11:11","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":211423,"visible":true,"origin":"","legend":"\u003cp\u003eThe flowchart of the selection of patients\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8159682/v1/5800ee0e131017464255989f.png"},{"id":106402712,"identity":"4f0b29a5-4b01-43ad-be95-58cf2c1adfae","added_by":"auto","created_at":"2026-04-08 09:12:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1383094,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8159682/v1/8b820f2e-750b-41d6-844e-4758c36f55cb.pdf"},{"id":98437372,"identity":"73eff800-b387-43c5-be12-3d31b217b676","added_by":"auto","created_at":"2025-12-17 16:57:15","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":38192,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryFiles.docx","url":"https://assets-eu.researchsquare.com/files/rs-8159682/v1/5d906909a37cf346401ec752.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Impact of Anti-Müllerian Hormone on Pregnancy Loss in Fresh and Frozen-thawed Embryo Transfer Cycles: A Retrospective Cohort Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eWith the continuous development of assisted reproductive technologies and the growing proportion of women of advanced maternal age, adverse pregnancy outcomes following in vitro fertilization (IVF) and embryo transfer have become a growing concern. Studies have shown that an increase in maternal age is associated with a decline in fertility and a higher risk of miscarriage[\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Miscarriage can harm women's physical health and impose psychological and financial burdens, especially for those undergoing assisted reproduction. Consequently, timely assessment of miscarriage risk and appropriate interventions are vital for these patients.\u003c/p\u003e \u003cp\u003eAnti-M\u0026uuml;llerian hormone (AMH), produced by ovarian granulosa cells, plays a pivotal role in folliculogenesis[\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Ovarian reserve, which encompasses the quantity and quality of follicles in the ovarian pool, diminishes with advancing age[\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Serum AMH levels serve as an accurate marker of growing follicle count and are considered a reliable indicator of ovarian reserve and response[\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Consequently, AMH measurement has become a routine assessment in the field of assisted reproduction. Nevertheless, the extent to which AMH correlates with oocyte and embryo quality, as well as its potential influence on pregnancy outcomes, particularly miscarriage, remains to be fully elucidated.\u003c/p\u003e \u003cp\u003eCurrent studies on the correlation between serum AMH levels and miscarriage risk have conflicting conclusions. Some studies indicate that pre-pregnancy low AMH levels are linked to higher miscarriage risk. A systematic review and meta - analysis of 13 retrospective studies (N\u0026thinsp;=\u0026thinsp;12,042) shows that, compared to women with normal or high AMH levels, those with low AMH have a significantly increased miscarriage risk after assisted reproduction (\u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.004, OR\u0026thinsp;=\u0026thinsp;1.35, 95% CI\u0026thinsp;=\u0026thinsp;1.10\u0026ndash;1.66)\u003csup\u003e[13]\u003c/sup\u003e. A 2017 cohort study with 1,060 patients found that after adjusting for age and oocyte number, low baseline serum AMH raises the risk of early miscarriage after fresh embryo transfer (\u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.021)[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], a prospective study on natural conception found that compared to women with normal AMH (\u0026ge;\u0026thinsp;1.0 ng/mL), those with severe ovarian reserve decline (AMH\u0026thinsp;\u0026le;\u0026thinsp;0.4 ng/mL) have a higher miscarriage risk (HR\u0026thinsp;=\u0026thinsp;2.3, CI\u0026thinsp;=\u0026thinsp;1.3\u0026ndash;4.3)[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. However, other studies suggest high AMH levels may also be an independent miscarriage risk factor, possibly due to endocrine changes, similar to those in polycystic ovary syndrome (PCOS). A domestic retrospective study found that in young women, high pre-pregnancy AMH levels (\u0026gt;\u0026thinsp;3.99 ng/mL) increase early miscarriage risk after fresh embryo transfer, and this was consistent in the non - PCOS subgroup[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Additionally, a prospective study on patients with natural conception showed that both low (AMH\u0026thinsp;\u0026lt;\u0026thinsp;1.1 ng/mL) and high (AMH\u0026thinsp;\u0026gt;\u0026thinsp;4.5 ng/mL) serum AMH levels during pregnancy are independent risk factors for early natural miscarriage (both \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.05)[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. In conclusion, despite extensive research on AMH and miscarriage risk, the clinical predictive value of AMH remains controversial, due to inconsistent findings.\u003c/p\u003e \u003cp\u003eMoreover, existing studies have some limitations. On the one hand, the predictive ability of AMH may be affected by age, the type of conception (natural conception and assisted reproductive technology), the cause of miscarriage (embryo-origin and maternal-origin) and so on, while some studies fail to conduct stratified analyses of the study population. On the other hand, some studies inadequately control for confounding factors. For example, certain studies may include PCOS patients so that the association between their high AMH levels and miscarriage might be mediated by obesity and metabolic disorders rather than AMH itself.\u003c/p\u003e \u003cp\u003eGiven that, the retrospective cohort study included the patients from our hospital who underwent IVF and achieved clinical pregnancy. By analyzing pre - pregnancy serum AMH levels, it explores the link between the levels of AMH and miscarriage risk following embryo transfer across different age groups and different types of embryo transfer. The study aims to illuminate the impact of diminished ovarian reserve on assisted reproductive outcomes. It seeks to supply robust evidence for pre - treatment evaluation and pregnancy management in assisted reproductive patients and to advance the clinical application of serum AMH levels.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was approved by the Ethics Committee of Peking University Third Hospital Reproductive Center (2022-580-01) and adhered to the principle of the Declaration of Helsinki. As the study involved retrospective data analysis without personally identifiable information, the requirement for informed consent was waived. (Clinical trial number: not applicable.)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe retrospective cohort study was conducted at Peking University Third Hospital Reproductive Center from January 1, 2017, to December 31, 2020. The study consisted of patients who underwent IVF/ICSI and achieved singleton clinical pregnancies through fresh or frozen-thawed embryo transfer. For each patient, only their first clinical pregnancy within the study period was included in the analysis to evaluate miscarriage outcomes. The process for selecting participants is shown in \u003cstrong\u003eFigure 1\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eSelection and description of the participants\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study included participants who met the following criteria:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e(1)Aged 20 - 45 years; (2)Serum AMH levels measured before ovarian stimulation, within 2 years prior to embryo transfer; (3)Singleton clinical pregnancy achieved after transfer of 1 or 2 embryos.\u003c/p\u003e\n\u003cp\u003ePatients presenting any of the following were excluded:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e(1)Uterine malformations (e.g.: unicornuate, hemiunicornuate, or septate uterus) or intrauterine adhesions; (2)Chromosomal abnormalities in either partner; (3)Autoimmune diseases (e.g.: Sj\u0026ouml;gren\u0026apos;s syndrome, systemic lupus erythematosus, or antiphospholipid syndrome); (3)Recurrent miscarriage (\u0026ge;2 consecutive natural miscarriages with the same partner); (4)PCOS, diagnosed per the Rotterdam criteria[18]: at least two of oligomenorrhea / amenorrhea, clinical/biochemical hyperandrogenism, or polycystic ovaries on ultrasound, after excluding other hyperandrogenic etiologies; (5)Oocyte donation or in vitro maturation (IVM) cycles; (6)Loss to follow - up of pregnancy outcomes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eResearch group\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBased on clinical practice and the data characteristics of this study, this study used the 2019 ACOG criteria[19], defining AMH \u0026lt;1.00 ng/mL as low. Participants were categorized into two groups: low AMH (AMH \u0026lt;1.00 ng/mL) and normal AMH (AMH \u0026ge;1.00 ng/mL), according to their serum AMH levels measured before ovarian stimulation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eProtocol\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll participants underwent controlled ovarian hyperstimulation (COH) following the center\u0026apos;s standard protocol. Clinicians selected COH protocols and drug doses by considering patients\u0026apos; age, AFC, AMH levels, basal sex hormone levels, prior IVF retrieved oocytes yield. The primary COH protocols included the GnRH - a long protocol, the ultralong protocol, the short protocol, or the GnRH antagonist protocol. Less than 5% of participants used non- traditional COH protocols, such as mild stimulation protocol, natural cycle protocol, or luteal phase stimulation protocol.\u003c/p\u003e\n\u003cp\u003e(1) GnRH - a long protocol: GnRH - a is administered on day 2 of the menstrual cycle or in the luteal phase. After 14 - 21 days, once pituitary down - regulation is achieved (LH \u0026lt;5~10 IU/L, E2 \u0026lt;50 pg/mL, endometrium \u0026lt;4~5 mm, no functional ovarian cysts), exogenous Gn is started, and GnRH - a continues.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e(2) GnRH - a ultralong protocol: Long - acting GnRH - a is given on day 2 of the menstrual cycle, repeated after 28 days, and Gn is started 14 days later based on FSH, LH, E2, follicle size and number.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e(3) GnRH - a short protocol: Short - acting GnRH - a is administered on day 2 of the menstrual cycle, and Gn is started on day 3.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e(4) Antagonist protocol: Gn is administered daily starting on day 2 or 3 of the menstrual cycle. After 6 days or when at least one follicle reaches 12 mm in diameter, GnRH - antagonist is added.\u003c/p\u003e\n\u003cp\u003eThe starting dose of Gn was determined by the patient\u0026apos;s age, AFC, basal FSH, and body surface area, usually 112.5 - 300 IU/day. After 4 - 5 days, ultrasound and hormone tests monitored follicle growth, and Gn dosage was adjusted When at least two follicles reached \u0026ge;18 mm, hCG was administered, and oocyte retrieval followed 34 - 38 hours later. Fertilization was via IVF or ICSI based on sperm quality or the need for pre - implantation genetic testing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eEmbryo transfer and follow-up\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients planned for fresh embryo transfer received luteal support beginning on the oocyte retrieval day. In our center, D3 embryos with \u0026ge;4 cells and \u0026le;30% fragmentation were regarded as viable for transfer, and blastocysts meeting the Gardner standard (\u0026ge;4BC or 4CB) were eligible for transfer. All patients underwent blood \u0026beta;-hCG testing 14 days after embryo transfer, with a level \u0026gt;25 IU/L suggesting a chemical pregnancy. Vaginal ultrasound was conducted 30 - 40 days post - transfer to check for gestational sac and fetal heartbeat, confirming clinical pregnancy. Pregnancy outcomes were monitored through telephone follow - up.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eData Collection\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBaseline clinical data, basal hormone levels (including serum AMH), COH protocols, drug doses, details of embryo transfer, and pregnancy outcomes were collected for all participants. All clinical pregnancy cohort data were obtained from the Reproductive Center\u0026apos;s clinical database.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eOutcome measures\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study\u0026apos;s outcome measures were as follows:\u0026nbsp;\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eMiscarriage was defined as pregnancy termination before 28 weeks\u0026apos; gestation or delivery of a fetus weighing \u0026lt;1000 g.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eEarly miscarriage was pregnancy termination before 12 weeks\u0026apos; gestation.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eLate miscarriage was pregnancy termination at or after 12 weeks\u0026apos; gestation.\u0026nbsp;\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eThe primary outcome was the miscarriage rate, calculated as:\u003c/p\u003e\n\u003cp\u003e(1) Miscarriage\u0026nbsp;rate=Number\u0026nbsp;of\u0026nbsp;miscarriages/Total\u0026nbsp;clinical\u0026nbsp;pregnancies\u0026times;100%\u003c/p\u003e\n\u003cp\u003eSecondary outcomes were the early and late miscarriage rates, calculated as:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eEarly\u0026nbsp;miscarriage\u0026nbsp;rate=Number\u0026nbsp;of\u0026nbsp;early\u0026nbsp;miscarriages/Total\u0026nbsp;clinical\u0026nbsp;pregnancies \u0026times;100%\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;Late miscarriage rate=Number of late miscarriages/Total clinical pregnancies \u0026times;100%\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the statistical data were analyzed by using the SPSS 25.0 software (SPSS, Inc, Chicago, IL, USA). For continuous variables, data adhering to a normal distribution were reported as mean \u0026plusmn; standard deviation (SD), and those without as median (interquartile range). Categorical variables were expressed as frequencies (percentages). Shapiro-Wilk tests assessed normality, and Levene\u0026apos;s tests checked the homogeneity of variances for continuous data across groups. Skewness and kurtosis were additionally evaluated for normality assessment when Shapiro-Wilk results were borderline (absolute values \u0026gt;2 considered non-normal). Groups with continuous data meeting homogeneity and normality were compared using independent samples t-tests; non-parametric tests were used otherwise. Categorical variables were analyzed using Pearson\u0026apos;s chi-squared test or Fisher\u0026apos;s exact test, as appropriate. Binary logistic regression adjusted for a priori confounders (age, infertility duration) and clinically relevant variables identified in univariate analyses: COS protocols, Gn dosage, ICSI fertilization, and embryo transfer characteristics The Hosmer-Lemeshow test was used to evaluate the regression models\u0026apos; fit. Statistical significance was set at a two-sided P value＜0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eOur analysis included 10,260 embryo transfer cycles from Peking University Third Hospital, between January 2017 and December 2020, after applying the inclusion and exclusion criteria (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Of the included cycles, 4,982 were fresh embryo transfers (48.56%) and 5,278 were frozen - thawed embryo transfers (51.44%).\u003c/p\u003e \u003cp\u003e \u003cb\u003eBaseline characteristics, relevant IVF data and pregnancy outcomes of patients following fresh or frozen-thawed embryo transfer\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe baseline characteristics and pregnancy outcomes of patients undergoing fresh or frozen - thawed embryo transfer are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Among 10,260 eligible cycles, 4,982 (48.6%) were fresh embryo transfers (FET) and 5,278 (51.4%) frozen-thawed embryo transfers (FET).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline characteristics, relevant IVF-ET data and pregnancy outcomes of patients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup 1\u003csup\u003e\u0026Dagger;\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;1017)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup 2\u003csup\u003e\u0026Dagger;\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;3965)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eχ\u003csup\u003e2\u003c/sup\u003e/Z value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, median (IQR\u003csup\u003e*\u003c/sup\u003e), year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35.00\u003c/p\u003e \u003cp\u003e(31.00, 37.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.00\u003c/p\u003e \u003cp\u003e(29.00, 35.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u003csup\u003e*\u003c/sup\u003e, median (IQR), kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.07\u003c/p\u003e \u003cp\u003e(20.23, 24.60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21.90\u003c/p\u003e \u003cp\u003e(20.10, 24.20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrimary Infertility, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e54.6\u003c/p\u003e \u003cp\u003e(555/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58.9 (2336/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfertile duration, median (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (2, 6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (2, 5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. of parity, median (IQR), times\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0, 1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0, 1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. of gravidity,\u003c/p\u003e \u003cp\u003emedian (IQR), times\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0, 0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0, 0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.24\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFSH\u003csup\u003e*\u003c/sup\u003e, median (IQR), (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.81\u003c/p\u003e \u003cp\u003e(5.98, 10.10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.51\u003c/p\u003e \u003cp\u003e(5.24, 7.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. of AFC\u003csup\u003e*\u003c/sup\u003e, median (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (4, 7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (7, 13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-28.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFallopian tube factors, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e32.1\u003c/p\u003e \u003cp\u003e(326/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39.6 (1570/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEndometriosis, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.0 (122/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.5 (339/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale factors, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49.1\u003c/p\u003e \u003cp\u003e(499/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e54.3 (2153/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThyroid disease, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.9 (19/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.1 (83/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.343\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUterine Fibroid, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10.5 (107/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.9 (275/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFailure of IVF\u003csup\u003e*\u003c/sup\u003e, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.5 (310/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.9 (788/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e52.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProtocol of COS\u003csup\u003e*\u003c/sup\u003e, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e132.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUltralong protocol\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.8 (120/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16.9 (671/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLong GnRH\u003csup\u003e*\u003c/sup\u003e agonist\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.5 (239/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e29.4 (1166/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGnRH agonist\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57.0\u003c/p\u003e \u003cp\u003e(580/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e52.1 (2065/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003csup\u003e\u003cb\u003e\u0026dagger;\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.7 (78/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.6 (63/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGn\u003csup\u003e*\u003c/sup\u003e dosage, median (IQR), U\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3425\u003c/p\u003e \u003cp\u003e(2606, 4350)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2575\u003c/p\u003e \u003cp\u003e(1950, 3375)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGn duration, median (IQR), day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11 (9, 13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11 (10, 13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-2.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.039\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eICSI\u003csup\u003e*\u003c/sup\u003e, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.4\u003c/p\u003e \u003cp\u003e(289/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38.2 (1514/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e33.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleavage stage embryo,\u003c/p\u003e \u003cp\u003epercentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.4 (248/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.7 (543/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e68.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlastocysts, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.2 (33/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.3 (250/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiscarriage, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.0 (264/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.2 (760/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEarly Miscarriage, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.9 (223/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15.6 (618/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLate Miscarriage, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.0 (41/1017)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.6 (141/3965)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.393\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.531\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e*\u003c/sup\u003eAbbreviations: IQR, interquartile range; BMI, body mass index; FSH, follicle-stimulating hormone; AFC, antral follicle counting; IVF, in vitro fertilization; COS, controlled ovarian stimulation; GnRH, gonadotropin-releasing hormone; Gn, gonadotropin; ICSI, intracytoplasmic sperm injection\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cb\u003e\u0026dagger;\u003c/b\u003e\u003c/sup\u003eOthers include the short protocol, the micro-stimulation protocol and the luteal-phase ovulation induction protocol\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cb\u003e\u0026Dagger;\u003c/b\u003e\u003c/sup\u003eGroup 1: women with low level of AMH (\u0026lt;1.00 ng/ml) and following fresh embryo transfer\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eGroup 2: women with normal level of AMH (\u0026ge;\u0026thinsp;1.00 ng/ml) and following fresh embryo transfer\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline characteristics, relevant IVF-FET data and pregnancy outcomes of patients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup 3\u003csup\u003e\u0026Dagger;\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;486)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup 4\u003csup\u003e\u0026Dagger;\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;4792)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eχ\u003csup\u003e2\u003c/sup\u003e/Z value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, median (IQR\u003csup\u003e*\u003c/sup\u003e), year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34.00\u003c/p\u003e \u003cp\u003e(31.00, 37.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.00\u003c/p\u003e \u003cp\u003e(29.00, 35.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI\u003csup\u003e*\u003c/sup\u003e, median (IQR), kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.80\u003c/p\u003e \u003cp\u003e(20.10, 24.40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21.60\u003c/p\u003e \u003cp\u003e(19.80, 23.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.026\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrimary Infertility, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e58.2\u003c/p\u003e \u003cp\u003e(283/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e61.4 (2941/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfertile duration, median (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (2, 6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (2, 5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.011\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. of parity, median (IQR), times\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0, 1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0, 1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.929\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. of gravidity,\u003c/p\u003e \u003cp\u003emedian (IQR), times\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0, 0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0, 0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.408\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFSH\u003csup\u003e*\u003c/sup\u003e, median (IQR), (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.51\u003c/p\u003e \u003cp\u003e(5.82, 9.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.22\u003c/p\u003e \u003cp\u003e(5.04, 7.42)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. of AFC\u003csup\u003e*\u003c/sup\u003e, median (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (4, 9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11 (8, 14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFallopian tube factors,\u003c/p\u003e \u003cp\u003epercentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.8\u003c/p\u003e \u003cp\u003e(179/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44.5 (2134/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEndometriosis, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.0 (68/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.1 (389/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale factors, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52.5\u003c/p\u003e \u003cp\u003e(255/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58.9 (2823/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThyroid disease, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.9 (9/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.0 (96/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.82\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUterine Fibroid, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.4 (41/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.4 (307/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.086\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFailure of IVF\u003csup\u003e*\u003c/sup\u003e, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.7 (149/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.3 (830/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProtocol of COS\u003csup\u003e*\u003c/sup\u003e, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e105.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUltralong protocol\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.8 (33/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.9 (568/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLong GnRH\u003csup\u003e*\u003c/sup\u003e agonist,\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.6 (105/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e28.1 (1347/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGnRH agonist\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64.0\u003c/p\u003e \u003cp\u003e(311/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e58.6 (2810/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003csup\u003e\u003cb\u003e\u0026dagger;\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.6 (37/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.4 (67/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGn\u003csup\u003e*\u003c/sup\u003e dosage, median (IQR), U\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3150\u003c/p\u003e \u003cp\u003e(2475, 3881)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2250\u003c/p\u003e \u003cp\u003e(1662.5, 3000)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGn duration, median (IQR), day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11 (9, 12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11 (10, 12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-2.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.025\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProtocol of Endometrial Preparation, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.161\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNatural cycle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61.7\u003c/p\u003e \u003cp\u003e(300/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57.6 (2759/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eArtificial cycle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.5\u003c/p\u003e \u003cp\u003e(139/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.5 (1460/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOvarian stimulation cycle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.5 (46/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.6 (558/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eICSI\u003csup\u003e*\u003c/sup\u003e, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.8\u003c/p\u003e \u003cp\u003e(140/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43.7 (2091/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e39.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCleavage stage embryo,\u003c/p\u003e \u003cp\u003epercentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e73.3\u003c/p\u003e \u003cp\u003e(356/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66.3 (3179/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlastocysts, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e72.8\u003c/p\u003e \u003cp\u003e(354/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66.5 (3188/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiscarriage, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23.0 (112/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18.5 (887/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.018\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEarly Miscarriage, percentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20.2 (98/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15.9 (764/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.020\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLate Miscarriage,\u003c/p\u003e \u003cp\u003epercentage (No./N)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.9 (14/486)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.5 (122/4792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.769\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e*\u003c/sup\u003eAbbreviations: IQR, interquartile range; BMI, body mass index; FSH, follicle-stimulating hormone; AFC, antral follicle counting; IVF, in vitro fertilization; COS, controlled ovarian stimulation; GnRH, gonadotropin-releasing hormone; Gn, gonadotropin; ICSI, intracytoplasmic sperm injection\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cb\u003e\u0026dagger;\u003c/b\u003e\u003c/sup\u003eOthers include the short protocol, the micro-stimulation protocol and the luteal-phase ovulation induction protocol\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cb\u003e\u0026Dagger;\u003c/b\u003e\u003c/sup\u003eGroup 3: women with low level of AMH (\u0026lt;1.00 ng/ml) and following frozen-thawed embryo transfer\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eGroup 4: women with normal level of AMH (\u0026ge;\u0026thinsp;1.00 ng/ml) and following frozen-thawed embryo transfer\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eSignificant baseline differences existed between AMH groups (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) in fresh embryo transfer cycles: The low AMH group (\u0026lt;\u0026thinsp;1.00 ng/mL) was older (median 35 vs. 32 years, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001), had higher FSH (7.81 vs. 6.51 IU/L, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001), and lower AFC (6 vs. 10, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001). Notably, the low AMH group had higher rates of endometriosis (12.0% vs. 8.5%, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.001) and prior IVF failure (30.5% vs. 19.9%, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001), suggesting residual confounding despite stratification. In IVF - related parameters, the low AMH group used more Gn (Z\u0026thinsp;=\u0026thinsp;17.84, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) but for a shorter time (Z=-2.06, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.039), had a lower ICSI rate (χ\u0026sup2;=33.44, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001), and a higher cleavage stage embryo or blastocyst transfer rate (χ\u0026sup2;=68.46 and 13.89, both \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001). Regarding pregnancy outcomes, the low AMH group had higher miscarriage and early miscarriage rates (χ\u0026sup2;=22.45 and 22.74, both \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001), with no significant difference in late miscarriage rates (χ\u0026sup2;=0.393, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.531).\u003c/p\u003e \u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, in frozen - thawed embryo transfer cycles, the low AMH group (N\u0026thinsp;=\u0026thinsp;486) had higher age (Z\u0026thinsp;=\u0026thinsp;11.34, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), longer infertility duration (Z\u0026thinsp;=\u0026thinsp;2.54, P\u0026thinsp;=\u0026thinsp;0.011), higher BMI (Z\u0026thinsp;=\u0026thinsp;2.23, P\u0026thinsp;=\u0026thinsp;0.026) and a slightly lower rate of primary infertility (χ\u0026sup2; = 1.88, P\u0026thinsp;=\u0026thinsp;0.170) than the normal AMH group (N\u0026thinsp;=\u0026thinsp;4,792). Basal FSH was higher (Z\u0026thinsp;=\u0026thinsp;10.23, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and AFC was lower (Z = -21.93, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) in the low AMH group. In terms of infertility causes, the low AMH group had fewer tubal - factor cases (χ\u0026sup2; = 10.32, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001) but more endometriosis cases (χ\u0026sup2; = 18.52, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with no significant difference in uterine - fibroid cases (χ\u0026sup2; = 2.95, P\u0026thinsp;=\u0026thinsp;0.086). Prior IVF failure was more common in the low AMH group (χ\u0026sup2; = 51.08, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). There were also differences in protocols of COS (χ\u0026sup2;=105.35, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001), with the low AMH group using more Gn (Z\u0026thinsp;=\u0026thinsp;14.92, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) but for a shorter time (Z=-2.25, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.025). The low AMH group had a lower ICSI rate (χ\u0026sup2;=39.76, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) and higher rates of cleavage stage embryo (χ\u0026sup2;=5.89, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.015) and blastocyst transfer (χ\u0026sup2;=7.62, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.006). In pregnancy outcomes, the low AMH group had higher miscarriage (χ\u0026sup2;=5.62, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.018) and early miscarriage rates (χ\u0026sup2;=5.45, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.020), with no significant difference in late miscarriage rates (χ\u0026sup2;=0.09, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.769).\u003c/p\u003e \u003cp\u003e \u003cb\u003eComparison of fresh embryo transfer pregnancy outcomes in women aged \u0026lt;35 and \u0026ge;\u0026thinsp;35 with Different AMH Levels\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe study showed that in both fresh and frozen - thawed embryo transfer cycles, the low AMH group exhibited higher miscarriage and early miscarriage rates than the normal AMH group. However, significant differences in baseline characteristics and IVF related data were found between the different AMH groups across these cycles. To better analyze how AMH levels relate to pregnancy outcomes, it is necessary to better match the differences between groups. Patients were stratified into two age subgroups (\u0026ge;\u0026thinsp;35 and \u0026lt;\u0026thinsp;35 years) to account for differences in baseline data and IVF treatment processes. Tables\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e provide detailed results of the comparisons within these subgroups.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBinary logistic regression analysis of pregnancy outcomes of fresh embryo transfer in IVF cycles\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcomes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eAged\u0026thinsp;\u0026ge;\u0026thinsp;35\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eAged\u0026thinsp;\u0026lt;\u0026thinsp;35\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR\u003csup\u003e*\u003c/sup\u003e (95%CI\u003csup\u003e*\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003csup\u003e\u003cb\u003e\u0026dagger;\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR (95%CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiscarriage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.03 (0.79\u0026thinsp;~\u0026thinsp;1.32)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.33 (1.02\u0026thinsp;~\u0026thinsp;1.73)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.036\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEarly Miscarriage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.04 (0.79\u0026thinsp;~\u0026thinsp;1.36)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.788\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.38 (1.04\u0026thinsp;~\u0026thinsp;1.83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.028\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLate Miscarriage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.96 (0.56\u0026thinsp;~\u0026thinsp;1.65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.887\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.09 (0.61\u0026thinsp;~\u0026thinsp;1.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.768\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e*\u003c/sup\u003eAbbreviations: OR, odds ratio; CI, confidence intervals; LH, luteinizing hormone; Gn, gonadotropin; E2, estradiol.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cb\u003e\u0026dagger;\u003c/b\u003e\u003c/sup\u003eAdjusted for age, BMI, infertile factor, Gn dosage, protocol of COS, ICSI, type of embryos transferred, number of embryos transferred. The model was tested by Hosmer-Lemeshow.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBinary logistic regression analysis of pregnancy outcomes of frozen-thawed embryo transfer in IVF cycles\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutcomes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eAged\u0026thinsp;\u0026ge;\u0026thinsp;35\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eAged\u0026thinsp;\u0026lt;\u0026thinsp;35\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOR\u003csup\u003e*\u003c/sup\u003e (95%CI\u003csup\u003e*\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003csup\u003e\u003cb\u003e\u0026dagger;\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOR (95%CI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP value\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiscarriage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.95(0.66\u0026thinsp;~\u0026thinsp;1.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.802\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.06 (0.76\u0026thinsp;~\u0026thinsp;1.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.727\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEarly Miscarriage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.99 (0.67\u0026thinsp;~\u0026thinsp;1.48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.977\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.05(0.75\u0026thinsp;~\u0026thinsp;1.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.788\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLate Miscarriage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.78 (0.30\u0026thinsp;~\u0026thinsp;2.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.613\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.10 (0.48\u0026thinsp;~\u0026thinsp;2.53)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.828\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e*\u003c/sup\u003eAbbreviations: OR, odds ratio; CI, confidence intervals; LH, luteinizing hormone; Gn, gonadotropin; E2, estradiol.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cb\u003e\u0026dagger;\u003c/b\u003e\u003c/sup\u003eAdjusted for age, BMI, infertile factor, Gn dosage, protocol of COS, ICSI, type of embryos transferred, number of embryos transferred. The model was tested by Hosmer-Lemeshow.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAs indicated in Supplementary table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, among patients who were 35 years or older and achieved clinical pregnancies following fresh embryo transfer, there were 518 in the low AMH group and 1,149 in the normal AMH group. In terms of baseline data, the low AMH group had a significantly higher age (Z\u0026thinsp;=\u0026thinsp;4.20, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) but comparable BMI (P\u0026thinsp;=\u0026thinsp;0.995). The low AMH group also exhibited higher basal FSH (Z\u0026thinsp;=\u0026thinsp;8.59, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and lower AFC (Z = -17.13, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). They had a lower proportion of tubal factors (χ\u0026sup2; = 12.87, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). IVF failure was more common in the low AMH group (χ\u0026sup2; = 11.91, P\u0026thinsp;=\u0026thinsp;0.001). Additionally, the low AMH group used more Gn (Z\u0026thinsp;=\u0026thinsp;6.11, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) but for a shorter duration (Z = -2.46, P\u0026thinsp;=\u0026thinsp;0.014), had a lower ICSI rate (χ\u0026sup2; = 4.80, P\u0026thinsp;=\u0026thinsp;0.028), and a higher rate of cleavage stage embryo (χ\u0026sup2; = 34.15, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and blastocyst transfer (χ\u0026sup2; = 5.68, P\u0026thinsp;=\u0026thinsp;0.017). Regarding pregnancy outcomes, the miscarriage rate was 30.9% in the low AMH group and 28.5% in the normal AMH group, with no significant difference (χ\u0026sup2; = 0.90, P\u0026thinsp;=\u0026thinsp;0.342). Similarly, no significant differences were found in early (26.3% vs. 23.2%, χ\u0026sup2; = 1.71, P\u0026thinsp;=\u0026thinsp;0.190) and late miscarriage rates (4.6% vs. 5.3%, χ\u0026sup2; = 0.21, P\u0026thinsp;=\u0026thinsp;0.645).\u003c/p\u003e \u003cp\u003eSupplementary table 2 shows that among patients under 35 with clinical pregnancies from fresh embryo transfer, 499 were in the low AMH group and 2,816 in the normal AMH group. The low AMH group had higher age (Z\u0026thinsp;=\u0026thinsp;5.88, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), slightly higher BMI (Z\u0026thinsp;=\u0026thinsp;2.21, P\u0026thinsp;=\u0026thinsp;0.027), and longer infertility duration (Z\u0026thinsp;=\u0026thinsp;2.75, P\u0026thinsp;=\u0026thinsp;0.006). They also had higher basal FSH (Z\u0026thinsp;=\u0026thinsp;8.39, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), lower AFC (Z = -20.51, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and a higher proportion of endometriosis (χ\u0026sup2; = 20.83, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). IVF failure was more common in the low AMH group (χ\u0026sup2; = 16.05, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The low AMH group used more Gn (Z\u0026thinsp;=\u0026thinsp;15.47, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), had a lower ICSI rate (χ\u0026sup2; = 17.92, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and a higher rate of cleavage stage embryo (χ\u0026sup2; = 20.11, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and blastocyst transfer (χ\u0026sup2; = 7.10, P\u0026thinsp;=\u0026thinsp;0.008). In pregnancy outcomes, the miscarriage rate was significantly higher in the low AMH group (20.8% vs. 15.4%, χ\u0026sup2; = 8.93, P\u0026thinsp;=\u0026thinsp;0.003), as was the early miscarriage rate (17.4% vs. 12.5%, χ\u0026sup2; = 8.56, P\u0026thinsp;=\u0026thinsp;0.003). No significant difference was found in late miscarriage rates (3.4% vs. 2.8%, χ\u0026sup2; = 0.30, P\u0026thinsp;=\u0026thinsp;0.584), suggesting AMH\u0026rsquo;s effect may be limited to early pregnancy loss.\u003c/p\u003e \u003cp\u003eThese results indicate that in patients under 35, low AMH levels are significantly associated with a higher risk of miscarriage following fresh embryo transfer, particularly in the case of early miscarriage.\u003c/p\u003e \u003cp\u003e \u003cb\u003eComparison of frozen-thawed embryo transfer pregnancy outcomes in women aged\u0026thinsp;\u0026ge;\u0026thinsp;35 and \u0026lt;35 with Different AMH Levels\u003c/b\u003e \u003c/p\u003e \u003cp\u003eAmong the clinical pregnancies from frozen - thawed embryo transfer, there were 486 in the low AMH group and 4,792 in the normal AMH group. Subgroup analysis was performed based on age (\u0026ge;\u0026thinsp;35 years and \u0026lt;\u0026thinsp;35 years), and the results of the comparison between the two groups are presented in Supplementary Tables\u0026nbsp;3 and 4.\u003c/p\u003e \u003cp\u003eAs shown in Supplementary table 3, among women aged 35 and older with clinical pregnancies from frozen - thawed embryo transfer, there were 229 in the low AMH group and 1,263 in the normal AMH group. The low AMH group had significantly higher age (Z\u0026thinsp;=\u0026thinsp;4.91, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), higher basal FSH (Z\u0026thinsp;=\u0026thinsp;6.93, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and lower AFC (Z = -12.57, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). They also had a lower rate of tubal factors (χ\u0026sup2; = 4.73, P\u0026thinsp;=\u0026thinsp;0.030) but a higher rate of endometriosis (χ\u0026sup2; = 6.71, P\u0026thinsp;=\u0026thinsp;0.010). IVF failure was more common in the low AMH group (χ\u0026sup2; = 9.28, P\u0026thinsp;=\u0026thinsp;0.002). The low AMH group used more Gn (Z\u0026thinsp;=\u0026thinsp;5.89, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) but for a shorter duration (Z = -2.56, P\u0026thinsp;=\u0026thinsp;0.010), had a lower ICSI rate (χ\u0026sup2; = 18.28, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and a higher rate of cleavage stage embryo (χ\u0026sup2; = 5.77, P\u0026thinsp;=\u0026thinsp;0.016) and blastocyst transfer (χ\u0026sup2; = 7.32, P\u0026thinsp;=\u0026thinsp;0.007). The differences in BMI (P\u0026thinsp;=\u0026thinsp;0.707), primary infertility rate (P\u0026thinsp;=\u0026thinsp;0.442), and infertility duration (P\u0026thinsp;=\u0026thinsp;0.486) between the two groups were not statistically significant. Among women aged\u0026thinsp;\u0026ge;\u0026thinsp;35 years, there was a higher miscarriage rate in the low AMH group (30.6%) compared to the normal AMH group (26.4%), but the difference was not statistically significant (χ\u0026sup2; = 1.47, P\u0026thinsp;=\u0026thinsp;0.226). Similarly, no significant differences were found in early miscarriage rates (27.1% vs. 23.1%, P\u0026thinsp;=\u0026thinsp;0.226) or late miscarriage rates (3.5% vs. 3.3%, P\u0026thinsp;=\u0026thinsp;1.000).\u003c/p\u003e \u003cp\u003eAs shown in Supplementary table 4, among women under the age of 35, there were 257 patients in the low AMH group and 3,529 in the normal AMH group. The low AMH group demonstrated significantly higher age (Z\u0026thinsp;=\u0026thinsp;5.43, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), significantly higher basal FSH levels (Z\u0026thinsp;=\u0026thinsp;6.86, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and significantly lower AFC (Z = -16.76, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Additionally, the low AMH group had a higher proportion of endometriosis cases (χ\u0026sup2; = 11.09, P\u0026thinsp;=\u0026thinsp;0.001), used a higher dosage of Gn (Z\u0026thinsp;=\u0026thinsp;12.55, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and had a lower ICSI rate (χ\u0026sup2; = 16.35, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). However, differences in infertility duration (P\u0026thinsp;=\u0026thinsp;0.669), cleavage stage embryo transfer rate (P\u0026thinsp;=\u0026thinsp;0.170), and blastocyst transfer rate (P\u0026thinsp;=\u0026thinsp;0.426) between the two groups were not statistically significant. In terms of pregnancy outcomes, the low AMH group had a miscarriage rate of 16.3% compared to 15.7% in the normal AMH group (χ\u0026sup2; = 0.04, P\u0026thinsp;=\u0026thinsp;0.844). Similarly, no significant differences were found in early miscarriage rates (14.0% vs. 13.4%, P\u0026thinsp;=\u0026thinsp;0.847) or late miscarriage rates (2.3% vs. 2.3%, P\u0026thinsp;=\u0026thinsp;1.000).\u003c/p\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eBinary logistic regression analysis of pregnancy outcomes\u003c/h2\u003e \u003cp\u003eFurther binary logistic regression analyses were performed for women aged\u0026thinsp;\u0026ge;\u0026thinsp;35 years and \u0026lt;\u0026thinsp;35 years. Variables included the miscarriage, early miscarriage and late miscarriage; and covariates like age, BMI, and variables with significant differences (\u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.05) in baseline data and IVF treatment between AMH groups.\u003c/p\u003e \u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, in fresh embryo transfer cycles, after controlling for confounding factors, low AMH levels were not significantly associated with miscarriage risk in women aged\u0026thinsp;\u0026ge;\u0026thinsp;35 (OR\u0026thinsp;=\u0026thinsp;1.03, 95% CI\u0026thinsp;=\u0026thinsp;0.79\u0026ndash;1.32, P\u0026thinsp;=\u0026thinsp;0.850). However, in women under 35, low AMH levels were significantly associated with miscarriage risk (OR\u0026thinsp;=\u0026thinsp;1.33, 95% CI\u0026thinsp;=\u0026thinsp;1.02\u0026ndash;1.73, P\u0026thinsp;=\u0026thinsp;0.036), particularly early miscarriage (OR\u0026thinsp;=\u0026thinsp;1.38, 95% CI\u0026thinsp;=\u0026thinsp;1.04\u0026ndash;1.83, P\u0026thinsp;=\u0026thinsp;0.028), while with no significant association with late miscarriage (OR\u0026thinsp;=\u0026thinsp;1.09, 95% CI\u0026thinsp;=\u0026thinsp;0.61\u0026ndash;1.98, P\u0026thinsp;=\u0026thinsp;0.768).\u003c/p\u003e \u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, in frozen - thawed embryo transfer cycles, after adjusting for confounding factors, low AMH levels were not significantly associated with miscarriage risk in women aged\u0026thinsp;\u0026ge;\u0026thinsp;35 years (OR\u0026thinsp;=\u0026thinsp;0.95, 95% CI\u0026thinsp;=\u0026thinsp;0.66\u0026ndash;1.39, P\u0026thinsp;=\u0026thinsp;0.802). Similarly, in women under 35, low AMH levels were not significantly associated with miscarriage risk (OR\u0026thinsp;=\u0026thinsp;1.06, 95% CI\u0026thinsp;=\u0026thinsp;0.76\u0026ndash;1.50, P\u0026thinsp;=\u0026thinsp;0.727), nor with early or late miscarriage risk (P\u0026thinsp;=\u0026thinsp;0.788 and P\u0026thinsp;=\u0026thinsp;0.828).\u003c/p\u003e \u003cp\u003eBinary logistic regression adjusted for age, BMI, COS protocol, and embryo transfer parameters confirmed low AMH as an independent risk factor for miscarriage in women\u0026thinsp;\u0026lt;\u0026thinsp;35 after fresh ET (adjusted-OR\u0026thinsp;=\u0026thinsp;1.33, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.036), but not in FET cycles or older women (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Notably, Gn dosage and endometriosis status did not fully explain this association (Hosmer - Lemeshow \u003cem\u003eP\u0026thinsp;\u0026gt;\u003c/em\u003e\u0026thinsp;0.05 for all models).\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe study analyzed 10,260 clinical pregnancies from embryo transfer, including 4,982 fresh and 5,278 frozen - thawed embryo transfer cycles, using serum AMH levels of 1.00 ng/mL as the classification threshold. Results showed that low AMH was linked to higher miscarriage risk in both fresh and frozen - thawed cycles. Subgroup analysis indicated this was significant only in women under 35 following fresh embryo transfer. Binary logistic regression revealed that low AMH was an independent risk factor for miscarriage and early miscarriage in fresh cycles for women under 35, even after adjusting for potential confounders. However, no significant association was found between AMH levels and miscarriage risk in women aged\u0026thinsp;\u0026ge;\u0026thinsp;35 following fresh embryo transfer or those following frozen-thawed embryo transfer.\u003c/p\u003e \u003cp\u003eOur findings suggest a correlation between serum AMH levels and the risk of early miscarriage following fresh embryo transfer, which varies with patient age. Advanced maternal age is the primary factor for early miscarriage in older patients. Conversely, in younger patients, low AMH levels (\u0026lt;\u0026thinsp;1.00 ng/mL) emerge as an independent risk factor for miscarriage. These results highlight the potential of AMH as a predictive biomarker for miscarriage risk in young women undergoing fresh embryo transfer, suggesting that pre-treatment AMH screening could guide personalized clinical interventions, such as intensified luteal support or preimplantation genetic testing, to mitigate early pregnancy loss.\u003c/p\u003e \u003cp\u003eSome previous studies align with parts of our findings. Tarasconi et al.[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] analyzed 1,060 fresh - embryo transfer pregnancies and found low AMH (AMH\u0026thinsp;\u0026lt;\u0026thinsp;1.6 ng/mL) linked to higher miscarriage risk (OR\u0026thinsp;=\u0026thinsp;1.07, 95% CI\u0026thinsp;=\u0026thinsp;1.03\u0026ndash;1.12, P\u0026thinsp;=\u0026thinsp;0.021), but only in women aged\u0026thinsp;\u0026gt;\u0026thinsp;33. Our age-stratified analysis contradicts this. This discrepancy may stem from different AMH thresholds (1.6 ng/mL in their study vs. 1.0 ng/mL in ours per ACOG guidelines), which can affect risk stratification. Moreover, in the study, even within age groups, significant age differences between AMH groups may confound results. Notably, Hong et al.[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]studied 848 infertile women, 206 of whom had early miscarriages. They found both age and serum AMH independently associated with early miscarriage (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.022). Other studies suggest no link between AMH levels and miscarriage. Zhang et al.'s[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] large retrospective study of 9,431 first - time IVF patients found no independent correlation between AMH levels (using the 25th and 75th percentiles as cutoffs) and miscarriage rates after fresh embryo transfer. Discrepancies between this study and ours may arise from different AMH cutoffs and the inclusion of PCOS patients or other disease - related factors in their study that could impact results.\u003c/p\u003e \u003cp\u003eAlthough our study shows low AMH is associated with miscarriage in women under 35 after fresh embryo transfer, the underlying mechanism is unclear. This may relate to several hypotheses combining AMH's physiological role and clinical application. Firstly, it might be associated with decreased oocyte quality. AMH, a key regulator secreted by granulosa cells in small follicles, reflects ovarian reserve depletion. Its reduction may indirectly impair oocyte maturation. Specific factors secreted by oocytes, such as GDF \u0026minus;\u0026thinsp;9 and BMP15, can act on granulosa cells and downregulate AMH expression[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Aged\u0026thinsp;\u0026ge;\u0026thinsp;37 show downregulated TGF - β-related protein expression (including AMH) in cumulus cells, which affects follicle development and oocyte maturation[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. AMH levels in young women may reduce oocyte quality and increase miscarriage risk. Notably, oocyte aging in women\u0026thinsp;\u0026ge;\u0026thinsp;35 may mask the impact of AMH, while young women with rapid ovarian reserve depletion are more prone to oocyte quality defects. Second, it might relate to AMH's impact on endometrial receptivity. Evidence shows that endometrial cells express AMH, AMHRⅡ, and molecules in the AMH - pathway like ALK3, Smads1, and Smads9, indicating a functional AMH signaling system in the endometrium[\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. However, the exact physiological role and mechanism of AMH are still unclear. Paulson et al.[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e] reported that AMHRⅡ expression in the endometrium varies with the menstrual cycle, and has a substantial increase in the luteal phase. Fu et al.[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] found that in women with recurrent implantation failure, AMHRⅡ expression in endometrial cells is higher, with downregulated estrogen and prolactin receptors and increased apoptosis in luteal - phase cells. Thus, AMH may affect pregnancy outcomes by binding to AMHRⅡ, inducing apoptosis, and disrupting decidualization. Lastly, ovarian stimulation protocols may play a role. Serum AMH is a reliable predictor of ovarian response and influences the choice of stimulation protocol and drug dose. Our data show that patients with low AMH levels often use the antagonist protocol and higher Gn doses. Our study controlled for the impact of ovarian stimulation protocols using binary logistic regression but did not account for Gn dosage. Wang et al.[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e] reported that in antagonist - protocol patients, the aneuploidy rate in miscarriage tissue and Preimplantation Genetic Testing for Aneuploidy (PGT - A) cycles was higher than in the GnRH - a long protocol group. Further research is needed to confirm the link between Gn dosage and aneuploidy or miscarriage.\u003c/p\u003e \u003cp\u003eThe study has several strengths over previous research. First, it has the largest sample size to date investigating the link between serum anti-M\u0026uuml;llerian hormone (AMH) levels and miscarriage risk, which enhances the credibility of our findings. Second, while prior studies have primarily focused on AMH as an ovarian reserve marker, our study extends this by examining its association with miscarriage risk, further filling a knowledge gap in this field. Moreover, our results have significant implications for clinical practice and policymaking. Our data suggest that young women with low AMH levels should be informed of their increased miscarriage risk during IVF, and clinicians should consider AMH levels when devising individualized treatment plans.\u003c/p\u003e \u003cp\u003eHowever, our study has several limitations. First, even though it has a large sample size, as a retrospective study itself, it might lead to selection bias. This could impact how widely the results can be applied and how reliable they are. Second, the absence of wet lab validation restricts the discussion of biological mechanisms underlying the results. Third, despite adjusting for confounders, residual confounding by unmeasured factors (e.g., embryonic aneuploidy rates) cannot be excluded. Lastly, the study cohort doesn't fully represent different races and ages, which might affect the reproducibility of the findings.\u003c/p\u003e \u003cp\u003eFuture studies should aim to strengthen the current evidence through prospective, multicenter designs with larger sample sizes. In addition, further research is needed to elucidate the underlying mechanisms through which low AMH levels contribute to an increased risk of miscarriage. It would also be valuable to investigate dynamic changes in AMH levels\u0026mdash;such as those occurring before and after ovarian stimulation or during early pregnancy\u0026mdash;to determine their potential predictive value for miscarriage.\u003c/p\u003e \u003cp\u003eThis retrospective study of 10,260 embryo transfer cycles shows that in women under 35, following fresh embryo transfer, low serum AMH (\u0026lt;\u0026thinsp;1.00 ng/mL) predicts increased miscarriage risk, especially in early pregnancy. It offers new insights into AMH as a biomarker and provides guidance for future clinical practice.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, AMH levels showed no link to miscarriage risk in women over 35 following fresh embryo transfer or those aged 20\u0026ndash;45 but following frozen embryo transfer. However, in women under 35 following fresh embryo transfer, low serum AMH (\u0026lt;\u0026thinsp;1.00 ng/mL) was found to predict higher miscarriage risk, particularly in early pregnancy. Young women with low AMH undergoing fresh embryo transfer may benefit from enhanced luteal support or preimplantation genetic testing. Future research should focus on exploring AMH's clinical potential and its applicability across different populations to improve women's reproductive health management.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eAMH Anti M\u0026uuml;llerian hormone\u003c/p\u003e\n\u003cp\u003eART Assisted reproductive technology\u003c/p\u003e\u003cp\u003eIVF In vitro fertilization\u003c/p\u003e\u003cp\u003eIVM In vitro maturation\u003c/p\u003e\u003cp\u003eCOH Controlled ovarian hyperstimulation\u003c/p\u003e\u003cp\u003eAFC Antral follicle counts\u003c/p\u003e\u003cp\u003eFSH Follicle-stimulating hormone\u003c/p\u003e\u003cp\u003eBMI Body mass index\u003c/p\u003e\u003cp\u003eCOS Controlled ovarian stimulation\u003c/p\u003e\u003cp\u003eGnRH Gonadotropin-releasing hormone\u003c/p\u003e\u003cp\u003eGn Gonadotropin\u003c/p\u003e\u003cp\u003eICSI Intracytoplasmic sperm injection\u003c/p\u003e\u003cp\u003eLH Luteinizing hormone\u003c/p\u003e\u003cp\u003eE2 Estradiol\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe appreciate the support from the clinical database of Peking University Third Hospital Reproductive Center.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMML, SL and ZYL took part in designing the study, analyzing data, interpreting data, writing and reviewing the manuscript. RQW, ZHZ and DM interpreted data and reviewed the manuscript. RL was responsible for the study concept, interpreting data,reviewing the manuscript and approving the final version.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by Clinical Key Incubation Project A of Peking University Third Hospital (BYSYZD2023022), the National Key R\u0026amp;D Program of China (2022YFC2702500, 2021YFC2700601, 2021YFC2700303), Natural Science National Foundation of China (81925013,82288102), the Frontiers Medical Center, Tianfu Jincheng Laboratory Foundation (Project No. TFJC2023010001) and the Key Projects of Yunnan Province Science and Technology Department(202302AA310044).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData will be made available on request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was approved by the Ethics Committee of Peking University Third Hospital Reproductive Center (2022-580-01) and adhered to the principle of the Declaration of Helsinki. As the study involved retrospective data analysis without personally identifiable information, the requirement for informed consent was waived. (Clinical trial number: not applicable.)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that there is no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHuman ethics and consent to participate declarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eEzoe K, Miki T, Akaike H, Shimazaki K, Takahashi T, Tanimura Y, et al. Maternal age affects pronuclear and chromatin dynamics, morula compaction and cell polarity, and blastulation of human embryos. Hum Reprod. 2023;38:387\u0026ndash;99.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJiang W, Zheng Z, Yan N, Yao S, Xie Q, Ni D, et al. Maternal age-related declines in live birth rate following single euploid embryo transfer: a retrospective cohort study. J Ovarian Res. 2025;18:24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNguyen DT, Archer H, Earle A, Petyak E, Collins C, Vaillant K, et al. Maternal age is associated with apoptotic gene abundance patterns in blastocoel fluid-conditioned media from euploid embryos: a pilot study. J Assist Reprod Genet. 2025;42:1651\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRacine C, Gen\u0026ecirc;t C, Bourgneuf C, Dupont C, Plisson-Petit F, Sarry J, et al. New Anti-M\u0026uuml;llerian Hormone Target Genes Involved in Granulosa Cell Survival in Women With Polycystic Ovary Syndrome. J Clin Endocrinol Metab. 2021;106:e1271\u0026ndash;89.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCalcaterra V, Rossi V, Massini G, Casini F, Zuccotti G, Fabiano V. Probiotics and Polycystic Ovary Syndrome: A Perspective for Management in Adolescents with Obesity. Nutrients. 2023, 15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaraviti E, Karaviti D, Kani ER, Chatziandreou E, Paschou SA, Psaltopoulou T, et al. The role of anti-M\u0026uuml;llerian hormone: insights into ovarian reserve, primary ovarian insufficiency, and menopause prediction. Endocrine. 2025;89:338\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBleil ME, Gregorich SE, Adler NE, Sternfeld B, Rosen MP, Cedars MI. Race/ethnic disparities in reproductive age: an examination of ovarian reserve estimates across four race/ethnic groups of healthy, regularly cycling women. Fertil Steril. 2014;101:199\u0026ndash;207.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHu L, Yang H, Luo H, Zhang Y, Wang X, Wei S, et al. Age-specific reference ranges and variation of anti-m\u0026uuml;lerian hormone in healthy Chinese women of reproductive and perimenopausal age: a nationwide population-based prospective multicenter cross-sectional study. Gynecol Endocrinol. 2025;41:2431230.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKotlyar AM, Seifer DB. Ethnicity/Race and Age-Specific Variations of Serum AMH in Women-A Review. Front Endocrinol (Lausanne). 2020;11:593216.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang X, Jin L, Mao YD, Shi JZ, Huang R, Jiang YN, et al. Evaluation of Ovarian Reserve Tests and Age in the Prediction of Poor Ovarian Response to Controlled Ovarian Stimulation-A Real-World Data Analysis of 89,002 Patients. Front Endocrinol (Lausanne). 2021;12:702061.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAndreu A, Flores L, M\u0026eacute;ndez M, Ibarzabal A, Casals G, Mercad\u0026eacute; I, et al. Impact of bariatric surgery on ovarian reserve markers and its correlation with nutritional parameters and adipokines. Front Endocrinol (Lausanne). 2024;15:1284576.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao J, Zhang S, Chen L, Liu X, Su H, Chen L, et al. Sphingosine 1-phosphate protects against radiation-induced ovarian injury in female rats-impact on mitochondrial-related genes. Reprod Biol Endocrinol. 2020;18:99.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBusnelli A, Somigliana E, Cirillo F, Levi-Setti PE. Is diminished ovarian reserve a risk factor for miscarriage? Results of a systematic review and meta-analysis. Hum Reprod Update. 2021;27:973\u0026ndash;88.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTarasconi B, Tadros T, Ayoubi JM, Belloc S, de Ziegler D, Fanchin R. Serum antim\u0026uuml;llerian hormone levels are independently related to miscarriage rates after in vitro fertilization-embryo transfer. Fertil Steril. 2017;108:518\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLyttle Schumacher BM, Jukic AMZ, Steiner AZ. Antim\u0026uuml;llerian hormone as a risk factor for miscarriage in naturally conceived pregnancies. Fertil Steril. 2018;109:1065\u0026ndash;e10711061.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu X, Han Y, Wang X, Zhang Y, Du A, Yao R, et al. Serum anti-M\u0026uuml;llerian hormone levels are associated with early miscarriage in the IVF/ICSI fresh cycle. BMC Pregnancy Childbirth. 2022;22:279.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKostrzewa M, Żyła M, Garnysz K, Kaczmarek B, Szyłło K, Grzesiak M. Anti-M\u0026uuml;llerian hormone as a marker of abortion in the first trimester of spontaneous pregnancy. Int J Gynaecol Obstet. 2020;149:66\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAbdalla MA, Deshmukh H, Mohammed I, Atkin S, Reid M, Sathyapalan T. The Effect of Free Androgen Index on the Quality of Life of Women With Polycystic Ovary Syndrome: A Cross-Sectional Study. Front Physiol. 2021;12:652559.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eInfertility Workup for the Women's Health Specialist. ACOG Committee Opinion, Number 781. Obstet Gynecol. 2019;133:e377\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHong S, Chang E, Han EJ, Min SG, Kim S, Kang MK, et al. The anti-Mullerian hormone as a predictor of early pregnancy loss in subfertile women. Syst Biol Reprod Med. 2020;66:370\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang B, Meng Y, Jiang X, Liu C, Zhang H, Cui L, et al. IVF outcomes of women with discrepancies between age and serum anti-M\u0026uuml;llerian hormone levels. Reprod Biol Endocrinol. 2019;17:58.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSilva MSB, Giacobini P. New insights into anti-M\u0026uuml;llerian hormone role in the hypothalamic-pituitary-gonadal axis and neuroendocrine development. Cell Mol Life Sci. 2021;78:1\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Edani T, Assou S, Ferri\u0026egrave;res A, Bringer Deutsch S, Gala A, Lecellier CH, et al. Female aging alters expression of human cumulus cells genes that are essential for oocyte quality. Biomed Res Int. 2014;2014:964614.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang J, Dicken C, Lustbader JW, Tortoriello DV. Evidence for a M\u0026uuml;llerian-inhibiting substance autocrine/paracrine system in adult human endometrium. Fertil Steril. 2009;91:1195\u0026ndash;203.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMohamed AA, Al-Hussaini TK, Hussein RS, Abdallah KS, Amer SA. The Impact of High Circulating Anti-M\u0026uuml;llerian Hormone on Endometrial Thickness and Outcome of Assisted Reproductive Technology in Women with Polycystic Ovarian Syndrome: A Cohort Study. J Hum Reprod Sci. 2022;15:370\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTal R, Seifer CM, Khanimov M, Seifer DB, Tal O. High serum Antimullerian hormone levels are associated with lower live birth rates in women with polycystic ovarian syndrome undergoing assisted reproductive technology. Reprod Biol Endocrinol. 2020;18:20.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePaulson M, Sahlin L, Hirschberg AL. Endometrial expression of anti-M\u0026uuml;llerian hormone and its type II receptor in women with polycystic ovary syndrome. Reprod Biomed Online. 2020;41:128\u0026ndash;37.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFu YX, Yang HM, OuYang XE, Hu R, Hu T, Wang FM. Assessment of Anti-Mullerian Hormone and Anti-Mullerian Hormone Type II Receptor Variants in Women with Repeated Implantation Failures. Reprod Sci. 2021;28:406\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang J, Zhang J, Zhao N, Ma Y, Wang X, Gou X, et al. The effect of ovarian stimulation on aneuploidy of early aborted tissues and preimplantation blastocysts: comparison of the GnRH agonist long protocol with the GnRH antagonist protocol. J Assist Reprod Genet. 2022;39:1927\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Anti - Müllerian Hormone, Embryo Transfer, Miscarriage","lastPublishedDoi":"10.21203/rs.3.rs-8159682/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8159682/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eAnti-M\u0026uuml;llerian hormone (AMH) is a key biomarker of ovarian reserve in assisted reproductive technology (ART). However, its association with miscarriage risk following embryo transfer remains controversial. This study aims to investigate the correlation between pre-pregnancy serum AMH levels and the risk of miscarriage in patients undergoing in vitro fertilization (IVF).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis retrospective cohort study analyzed 10,260 fresh and frozen-thawed embryo transfer cycles resulting in singleton clinical pregnancies at Peking University Third Hospital Reproductive Center during January 2017 to December 2020. Patients were categorized into low AMH (\u0026lt;\u0026thinsp;1.00 ng/mL) and normal AMH (\u0026ge;\u0026thinsp;1.00 ng/mL) groups. Miscarriage rates were compared, and binary logistic regression was employed to assess the association between AMH levels and spontaneous miscarriage.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eIn the fresh embryo transfer cohort (n\u0026thinsp;=\u0026thinsp;4,982), the low AMH group had significantly higher overall miscarriage (26.0% vs. 19.2%, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) and early miscarriage rates (21.9% vs. 15.6%, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) than the normal AMH group. This association was prominent in women under 35, who demonstrated higher miscarriage (20.8% vs. 15.4%, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.003) and early miscarriage rates (17.4% vs. 12.5%, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.003). After adjusting for confounders, low AMH remained an independent risk factor for miscarriage in women under the age of 35 (OR\u0026thinsp;=\u0026thinsp;1.33, 95% CI\u0026thinsp;=\u0026thinsp;1.02\u0026ndash;1.73, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.036). No significant association was found in women\u0026thinsp;\u0026ge;\u0026thinsp;35. In the frozen-thawed transfer cohort (n\u0026thinsp;=\u0026thinsp;5,278), the miscarriage rate (23.0% vs. 18.5%, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.018) and early miscarriage rate (20.2% vs. 15.9%, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.020) were significantly higher in the low AMH group. However, stratified analysis by age showed no significant association between AMH levels and any miscarriage outcome (all had \u003cem\u003eP\u0026thinsp;\u0026gt;\u003c/em\u003e\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eLow serum AMH is an independent risk factor for miscarriage after fresh embryo transfer in women under 35, but not in women\u0026thinsp;\u0026ge;\u0026thinsp;35. For frozen-thawed embryo transfer, AMH levels are not associated with miscarriage risk, regardless of age.\u003c/p\u003e\u003ch2\u003eClinical trial number:\u003c/h2\u003e \u003cp\u003enot applicable.\u003c/p\u003e","manuscriptTitle":"The Impact of Anti-Müllerian Hormone on Pregnancy Loss in Fresh and Frozen-thawed Embryo Transfer Cycles: A Retrospective Cohort Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-16 14:11:02","doi":"10.21203/rs.3.rs-8159682/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f9f516f9-e101-4b50-a75b-c72b4768c74e","owner":[],"postedDate":"December 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-04T13:56:13+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-16 14:11:02","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8159682","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8159682","identity":"rs-8159682","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}