The Impact of Previous Caesarean Delivery on IVF/ICSI Outcomes: A Retrospective Cohort Study on experience from Saudi Arabia

The Impact of Previous Caesarean Delivery on IVF/ICSI Outcomes: A Retrospective Cohort Study on experience from Saudi Arabia | 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 Previous Caesarean Delivery on IVF/ICSI Outcomes: A Retrospective Cohort Study on experience from Saudi Arabia Fatimah Al Zahrani, Sultanah Korkoman, Rawan Alqahtani, Rawan Albarakati, and 8 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7255223/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Introduction: The mode of prior delivery may significantly affect the success of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) and subsequent pregnancy outcomes. This study evaluates the impact of vaginal delivery (VD), Caesarean section (CS) without scar defect, and CS with scar defect (CSD) on IVF/ICSI outcomes. Materials and Methods In this study, 2284 women who underwent IVF/ICSI between 2020–2023 in Abha City, Saudi Arabia, were stratified into three groups: prior VD (Group I, *n* = 1109), CS without scar defect (Group II, *n* = 742), and CS with CSD (Group III, *n* = 433). Pregnancy outcomes were compared using binary logistic regression, adjusting for confounders. Results In this study, the differences between Groups I and II in live birth rates, implantation success, or clinical/ectopic pregnancy were found to be significant. However, Group III demonstrated significantly lower clinical pregnancy rates (27.9% vs. 63.3%, *p* < 0.05) and implantation success compared to Group I. Subgroup analysis revealed pronounced reductions in implantation, clinical pregnancy, and live birth rates among women ≤ 35 years in Group III versus Group I (*p* < 0.05). Conclusion CSD—but not CS alone—adversely affects IVF/ICSI outcomes, particularly in younger women. These findings underscore the importance of optimizing surgical techniques to prevent CSD formation and preserve fertility. Future studies should investigate strategies to enhance uterine healing post-CS and improve ART success rates. embryo transfer Caesarean scar defect clinical pregnancy embryo implantation IVF /ICSI 1. INTRODUCTION Cesarean section (CS) is one of the most critical surgical procedures frequently indicated during the process of delivery for safeguarding either the mother, baby, or both, particularly in the presence of obstetric disorders and high-risk pregnancies. The criteria for CS include maternal conditions of hypertensive disorder, haemorrhage, obstructed labour, fetal distress, malpresentation and history of previous uterine scars [ 1 , 2 ]. The World Health Organisation (WHO) believes that the ideal Cesarean Section (CS) ratio for a population in general should lie within 10% and 15%. This range aims to balance the benefits to mothers and newborns, while minimising unnecessary surgical risks at the same time. But the world trend nowadays is a considerable distance from this recommendation [ 3 ]. Many countries far exceed what they are supposed to be doing, placing global averages up around 20%. In several regions, CS rates have risen to a massive 40 ~ 50%, indicating an incommensurability with evidence-based obstetrics practice [ 3 , 4 ]. This alarming increase makes it crucial to ask which medical, cultural, and socio-economic factors enable the abuse of surgical birth? While CS can be life-saving, unnecessary procedures carry risks, including surgical complications, longer recovery times, and potential impacts on future pregnancies, including ectopic pregnancy, abnormal placentation, and uterine rupture [ 5 , 6 , 7 ]. In more than 50% of women, CS leads to post-cesarean scar defects (PCSD) [ 8 ]. Women with previous CSs could be at an increased risk of secondary subfertility and irregular vaginal bleeding [ 9 ]. Evidence also supports that CS can affect the implantation potential of assisted reproductive technology (ART) [ 10 , 11 ] and diminish the likelihood of embryo implantation [ 12 ] and cause pelvic pain [ 13 ]. The damaging effect of CS scar defect on childbirth outcome has been given more attention to currently. Several studies have found that CS scar defects can impede embryo implantation and lower the likelihood of conception after in vitro fertilization and embryo transfer (IVF-ET) [ 10 , 14 ]. Not with standing these findings, little is known about the mechanism through which CS scar defects disrupt the progression of pregnancy. There is uncertainty as to whether the anatomical changes imply uterine malfunction, which could limit the likelihood of optimal fertility, or if they genuinely impede the placement of embryos. Despite this fact, controversy over the therapeutic benefit of Caesarean section (CS) in women undergoing in vitro fertilization and embryo transfer (IVF–ET) continues today. Some studies indicate that CS defects may impair endometrial receptivity and embryo implantation, eventually leading to reduced IVF success rates [ 15 , 16 ], while other research shows no statistically significant differences between clinical pregnancy or live birth rates compared with control women who have never had CS [ 17 ].In this context, this study therefore evaluates the impact of VD, CS without a scar defect (CSD), and with a scar defect (CSD) on IVF/ICSI outcomes. 2. MATERIALS AND METHODS Study design This retrospective cross-sectional study was conducted between 2019 and 2023. The sample size was estimated by the rate of CS delivery using stratified analogous random sampling strategies with a 95% confidence interval. The hospital's electronic health records were utilized to assess the eligibility of the participants. This study included women between 20 and 40 years of age with secondary subfertility who had successful pregnancy(s) in the past and were treated either with a long mid-luteal GnRH agonist or a short GnRH antagonist protocol for IVF/ICSI stimulation. Women above 40 years were omitted. Similarly, women with morbidities including adenomyosis, intrauterine adhesion, uterine fibroids, congenital or acquired uterine malformations, parental chromosomal abnormalities, a history of recurrent spontaneous abortion, or a history of myomectomy or endometrioma resection were excluded. Study population : A total of 2,284 women fulfilled the eligibility requirements. Women were divided into three groups based on the mode of previous delivery and the occurrence of CS: Group I: Vaginal delivery (VD; n = 1,109); Group II: Previous delivery by CS but with no scar defect (CS; n = 742); and Group III: Previous CS with scar defect (CSD; n = 433). The participants were further stratified into age categories: ≤35 years and > 35 years. Patients in Group III were subdivided into: Group IIIa (n = 261): no fluid in the endometrial cavity; Group IIIb (n = 172): presence of fluid in the endometrial cavity. Diagnostic and Treatment Protocols CSD was evaluated and classified by competent sonographers using two-dimensional transvaginal ultrasonography. Patients underwent controlled ovarian hyperstimulation (COH) for the IVF/ICSI cycle (Vervoort et al., 2018). Serial blood tests for serum oestradiol concentration and transvaginal ultrasound scans were performed for all patients during the IVF stimulation phase. Ultrasound findings were collected on endometrial thickness, whether there was fluid in the uterine cavity, and the number and size of ovarian follicles. Participants underwent transvaginal oocyte retrieval (TVOR) 36 hours after the human chorionic gonadotropin (hCG) injection, per ASRM guidelines (2022) [ 18 ]. Embryos were transferred on day 3. In general, two embryos were transferred; however, in a few exceptional cases, three embryos were transferred, particularly when the patient was of advanced maternal age or had low-quality embryos. On days two or three following TVOR, patients were administered luteal support with progesterone. The IVF unit team collected details on the outcome of the IVF treatment cycle through follow-up calls with the patients. The live birth rate served as the primary outcome measure (Zegers-Hochschild et al., 2017) [ 19 ]. Positive hCG tests, clinical pregnancies, mean implantation rates, miscarriages, ectopic pregnancies, mode of delivery, and gestational age at birth were recorded. Data collection In this study, data were obtained from comprehensive reviews of electronic medical records, ultrasound reports, and structured interviews with patients who returned for follow-up. Baseline demographic information and clinical characteristics—including age, BMI, period of infertility, and obstetric history—were extracted from hospital records. Information on detailed IVF/ICSI cycle parameters, including stimulation protocols, doses of gonadotropins, endometrial thickness and follicular measurements, was retrieved from electronic health records and laboratory reports. Cesarean scar defects were assessed and graded by two independent sonographers with a standardised 2D transvaginal ultrasound imaging system. When were levels of serum estradiol and hCG test results obtained? Pregnancy outcomes, such as clinical confirmation of pregnancy, live birth, miscarriage and ectopic pregnancy, were confirmed through follow-up telephone interviews with the IVF clinical team. Postpartum medical records were examined for additional details of delivery—such as gestational age, birth weight and mode. To ensure the accuracy of our data, we used uniform extraction forms, and any discrepancies in data were solved by cross-referencing original clinical records. Statistical Analysis All data were maintained in MS-Excel, and analyses were carried out through GraphPad Prism (Ver. 5) and STATA (Ver. 11). Descriptive analyses were conducted, and the baseline characteristics across the three groups were compared using the SNK-q test, Pearson's χ2 test, ANOVA and the Kruskal-Wallis H test. Logistic and linear regressions were calculated. 3. RESULTS A total of 2,284 participants were included in the study, categorized into three groups: Group I (n = 1,109), Group II (n = 742), and Group III (n = 433) (Table 1 ). Baseline clinical parameters, including infertility aetiology, infertility type, stimulation protocols, and fertilisation method, did not differ significantly among the groups, suggesting that the presence of a cesarean scar did not affect early embryogenesis or fertilisation outcomes. All groups had similar rates of fertilization and number of embryos transferred. The groups did differ in some more critical respects. Compared with any of the three groups, the number of high-quality embryos for transplantation differed significantly (P < 0.05). The endometrial thickness on the day of the procedure was also strikingly thinner in Group III than in Groups I and II (P < 0.05). Moreover, Day 2 embryo transfers were proportionately greater in Group III than in the other two groups (P < 0.05). All three groups were broadly comparable in terms of baseline conditions and treatment parameters. In terms of age, BMI, and ovarian stimulation outcomes, no significant differences were seen among the three groups. The proportion of fertilized oocytes was likewise not significantly different (P > 1.05, NS: not statistically significant), thoughthey did show some variation between groups I and III (P"*<0.01). However, compared to Groups I and III, endometrial thickness was "significantly" smaller in Group II (0.80 ± 0.1 cm) (P = 0.032). Notably, Group III (CS with a scar defect) demonstrated distinct embryological patterns, including a higher proportion of Day 3 transfers (90.3% vs. 79.9–83.3%, P < 0.005) and a significantly lower number of excellent quality embryos transferred (P < 0.0001). These variations in endometrial characteristics and embryo quality metrics could be responsible for the differences in reproductive outcomes seen between treatment groups. Table 1 Sample characteristics, clinical presentation and treatment modalities in three groups Variable / Group# Group I Group II Group III P Value Sample size (N) 1109 742 433 Age (years) 34.0 ± 3.6 34.5 ± 4.1 35.3 ± 3.9 0.68 Infertility duration (years) 5.2 ± 4.1 5.8 ± 2.2 4.6 ± 3.8 0.048 Infertility cause, N (%) Tubal factor 485 (43.7) 436 (58.7) 168 (38.7) 0.305 Ovary factor 156 (14.1) 89 (11.9) 62 (14.3) Male factor 180 (16.2) 67 (9.02) 53 (12.2) Unexplained 82 (7.3) 53 (7.1) 48 (11.0) Combined 206 (18.5) 97 (13.1) 102 (23.5) Infertility category, N (%) Primary 108 (9.7) 39 (5.2) 29 (6.6) 0.668 Secondary 1001 (90.2) 703 (94.7) 404 (93.3) BMI (kg/m 2 ) 24.1 ± 1.9 23.9 ± 2.9 22.9 ± 3.1 0.802 Basal FSH (IU/L) 6.6 ± 2.0 7.1 ± 3.8 6.98 ± 2.6 0.188 Stimulation protocol, N (%) Md-luteal (Triptorelin) 667 (60.1) 599 (80.7) 293 (67.6) 0.887 Antagonist (Cetrorelix) 442 (39.8) 143 (19.2) 140 (32.3) Total gonadotropins (IU) 2889 ± 761 2812 ± 669 2800 ± 673 0.799 Duration of stimulation (days) 8.8 ± 0.5 8.9 ± 1.3 8.9 ± 0.99 0.818 E2 level at event day (ng/mL) 3.2 ± 1.8 3.0 ± 1.7 3.0 ± 1.7 0.978 Thickness of endometrium (cm) at event day 0.89 ± .06 0.80 ± .1 0.88 ± .21 0.032 Follicle number with a diameter ≥ 1.4 (cm) at event day 1.1 ± 0.4 1.0 ± 0.5 1.1 ± 0.5 0.422 Retrieved oocytes (N) 11.1 ± 6.6 10.1 ± 6.6 11.3 ± 4.4 0.290 Fertilization methods, N (%) IVF 832 (75.0) 558 (75.2) 298 (68.8) 0.712 ICSI 277 (25.0) 184 (24.8) 135 (31.1) Fertilization rate (%) 79.9 73.6 79.1 0.923 Cleavage rate (%) 98.9 98.7 98.3 0.710 Available embryos (N) 4(2,6) 4 (2,6) 3 (2,6) 0.632 Excellent quality embryos (N) 2 (1,4) 2 (1,4) 2 (1,4) 0.561 Number of embryos injected (N) 2 (1,2) 1 (1,2) 1 (1,2) 0.090 Day of Transfer, N (%) D2 185 (16.6) 149 (20.08) 42 (9.69) 0.005 D3 924 (83.3) 593 (79.9) 391 (90.3) Excellent quality embryo transplanted (N) 1 (1,2) 1 (1,1) 1 (1,1) < 0.0001 #, variables assessed before delivery; values in % or mean ± St.Dev Crude and adjusted ORs were assessed throughout, considering covariates such as age, infertility factors, body mass index (BMI), endometrial thickness on the trigger day, fertilization. fertilization method, number of transferred embryos, number of high-quality embryos transferred, and day of transfer (see Table 2 ), the differences in pregnancy outcome between Group I and Group II. Group III exhibited a significantly lower live birth rate compared to Group I (adjusted OR: 0.53), which was not significant. Even in unadjusted analyses, Group III had reduced rates of clinical pregnancy and positive hCG tests (crude OR: 0.49 and 0.53, respectively). The mean implantation rate in Group III was substantially lower than in Group I after adjusting for confounders (adjusted OR: 0.88). Early abortion and ectopic pregnancy rates did not differ significantly between Group III and Group I. Table 2 Comparison of pregnancy outcome in three groups Variables/ groups % (n/N) Crude OR Adjusted OR Live Births Group I 57% (631/1109) Ref. Ref. Group II 42% (308/742) 0.92 (0.78–1.09) 0.98 (0.83–1.17) Group III 39% (170/433) 0.41 (0.34–0.50) 0.53 (0.42–0.66) Positive hCG Test Group I 54% (599/1109) Ref. Ref. Group II 55% (411/742) 1.10 (0.94–1.29) 1.48 (1.23–1.78) Group III 23% (99/433) 0.53 (0.43–0.66) 0.73 (0.59–0.91) Clinical Pregnancy Group I 63% (703/1109) Ref. Ref. Group II 70% (521/742) 0.99 (0.85–1.15) 1.25 (1.06–1.48) Group III 28% (121/433) 0.49 (0.39–0.61) 0.62 (0.49–0.79) Mean Implantation rate# Group I 0.5 ± 0.3 Ref. Ref. Group II 0.4 ± 0.2 0.98 (0.84–1.13) 0.96 (0.82–1.11) Group III 0.3 ± 0.34 0.89 (0.75–1.06) 0.88 (0.72–1.07) Early Abortion Group I 11% (123/1109) Ref. Ref. Group II 14% (101/742) 1.43 (1.08–1.88) 1.69 (1.25–2.29) Group III 18% (78/433) 0.97 (0.73–1.30) 1.33 (0.95–1.85) Ectopic Pregnancy Group I 2.3% (25/1109) Ref. Ref. Group II 2.8% (21/742) 1.43 (0.78–2.62) 1.94 (1.00–3.76) Group III 4.3% (19/433) 0.96 (0.51–1.83) 1.83 (0.96–3.50) #, mean, St.Dev Table 3 . Pregnancy outcome in age stratified participants groups as depicted through binary logistic regression. In participants < 35 years, Group III (CS with scar defect) demonstrated significantly worse reproductive outcomes compared to Group I (vaginal delivery), including a 55% reduction in live birth rates (adjusted OR 0.27, *p*<0.001), 42% lower clinical pregnancy rates (adjusted OR 0.58, *p*<0.001), and a 3-fold increased risk of ectopic pregnancy (adjusted OR 3.01, *p*=0.001). In contrast, Group II (CS without defect) showed comparable outcomes to Group I in this age category. In women over the age of 35, live birth rates and clinical pregnancy rates were comparable at specific points between groups, regardless of age. However, those in Group II showed higher biochemical pregnancy rates(adjusted OR 1.73, P < 0.001). This group also had a higher incidence of early abortion(adjusted OR 2.08, P < 0.001). This suggests that cesarean section and age may interact. These findings highlight that CS scar defects disproportionately impair fertility outcomes in younger women, while advanced maternal age (> 35 years) may overshadow the impact of uterine scarring on IVF success . Table 3 Pregnancy outcome in age stratified participants groups as depicted through binary logistic regression Variables/ groups 35 years % (n/N) Crude OR Adjusted OR % (n/N) Crude OR Adjusted OR Live Births Group I 54% (306/566) Ref. Ref. 26% (141/543) 1.00 1.00 Group II 47% (180/383) 0.66 (0.53–0.83) 0.93 (0.73–1.18) 31% (111/359) 0.99 (0.76–1.29) 0.98 (0.73–1.30) Group III 32% (70/219) 0.26 (0.19–0.35) 0.27 (0.18–0.41) 32% (69/214) 0.83 (0.59–1.16) 0.91 (0.63–1.30) Positive hCG Test Group I 58% (326/566) Ref. Ref. 45% (243/543) 1.00 1.00 Group II 50% (191/383) 0.71 (0.58–0.88) 0.76 (0.61–0.95) 53% (190/359) 1.53 (1.21–1.94) 1.73 (1.34–2.22) Group III 32% (69/219) 0.36 (0.26–0.49) 0.58 (0.41–0.82) 26% (56/214) 0.69 (0.50–0.95) 1.02 (0.74–1.41) Clinical Pregnancy Group I 59% (366/566) Ref. Ref. 41% (222/543) 1.00 1.00 Group II 53% (202/383) 0.71 (0.58–0.88) 0.76 (0.61–0.95) 56% (201/359) 1.53 (1.22–1.93) 1.61 (1.28–2.02) Group III 38% (83/219) 0.36 (0.27–0.48) 0.58 (0.42–0.81) 29% (63/214) 0.72 (0.52–0.99) 0.94 (0.68–1.30) Mean Implantation rate# Group I 0.34 ± 0.39 Ref. Ref. Group II 0.36 ± 0.44 1.21 (0.96–1.52) 1.22 (0.97–1.54) Group III 0.33 ± 0.49 1.01 (0.78–1.32) 1.03 (0.78–1.35) Early Abortion Group I 10 (56/566) Ref. Ref. 21 (116/543) 1.00 1.00 Group II 10 (39/383) 0.91 (0.63–1.31) 1.06 (0.72–1.55) 32 (115/359) 2.01 (1.43–2.82) 2.08 (1.45–2.98) Group III 16 (36/219) 1.01 (0.66–1.54) 1.06 (0.68–1.66) 22 (47/214) 0.93 (0.62–1.39) 1.41 (0.89–2.21) Ectopic Pregnancy Group I 1.98 (11/566) Ref. Ref. 3.2 (17/543) 1.00 1.00 Group II 2.2 (8/383) 0.81 (0.37–1.77) 1.21 (0.53–2.78) 6.3 (22/359) 2.18 (1.05–4.55) 2.21 (1.03–4.71) Group III 8.9 (19/219) 1.83 (0.95–3.52) 3.01 (1.52–5.97) 0 NA NA #, mean ± St.Dev. To observe the effect of fluid in the endometrial cavity, participants in Group III were subdivided into two groups, and their pregnancy outcomes were assessed (Table 4 ). Impact of Endometrial Cavity Fluid in Women with Cesarean Scar Defects Subgroup analysis of Group III (CS scar defect) compared women with (IIIa, *n*=261) and without (IIIb, *n*=172) endometrial cavity fluid. After adjusting for confounders, no statistically significant differences were observed in live birth rates (adjusted OR 1.11), clinical pregnancy (adjusted OR 1.03), or positive hCG tests (adjusted OR 0.81). While IIIa exhibited numerically higher implantation rates (0.29 ± 0.36 vs. 0.21 ± 0.36), this did not translate to improved clinical outcomes. Complications (early abortion, ectopic pregnancy) were rare and did not differ meaningfully between subgroups. Table 4 Subgroup analysis of the respondents with or without fluid in the endometrial cavity Variable Subgroup IIIa (n = 261) Subgroup IIIb (n = 172) Crude OR Adjusted OR Live Birth 32% (83/261) 24% (41/172) 1.02 1.11 Positive hCG Test 42% (109/261) 31% (53/172) 0.76 0.81 Clinical Pregnancy 36% (94/261) 28% (48/172) 0.73 1.03 Mean Implantation 0.29 ± 0.36 0.21 ± 0.36 Early Abortion 5 0 Ectopic Pregnancy 0 1 Table 5 presents the delivery success and newborn health outcomes of the three groups that complied with IVF/ICSI-ET. The analysis of delivery modes revealed striking differences among groups. Women with prior vaginal deliveries (Group I) had significantly lower cesarean rates (56%) compared to those with previous cesarean sections (Groups II and III: 96–97%, p < 0.0001). Neonatal outcomes showed clinically significant trends, though not all reached statistical significance. Most notably, the cesarean scar defect group (Group III) demonstrated concerning patterns, including a substantially higher preterm birth rate (40% vs. 10–15% in other groups, p = 0.089) and a markedly lower full-term delivery rate (55% vs. 94–97%, p = 0.091). Twin births were most common in Group I (26%) and virtually absent in Group III (0%). Birth weights (3.13–3.27 kg) and low birth weight rates (6–12%) were comparable across all groups (p > 0.2). Table 5 Childbirth and neonatal conditions after embryo transfer Variable Group I Group II Group III P value Caesarean birth rate (%) 56% (353/631) 97% (298/308) 96% (163/170) < 0.0001 Twin birth rate (%) 26% (164/631) 8% (26/308) 0 - Full term birth rate (%) 94% (591/631) 97% (297/308) 55% (93/170 0.091 Pre-term birth rate (%) 15% (93/631) 10% (31/308) 40% (68/170) 0.089 Birth weight (Kgs) 3.27 ± .59 3.22 ±. 60 3.13 ± .41 0.213 Low weight birth rate (%) 12% (73/631) 9% (29/308) 6% (11/170) 0.533 4. DISCUSSION This retrospective analysis, based on the large sample of IVF/ICSI-ET, found no significant differences in pregnancy outcomes between women in Groups I and II. However, the likelihood of subsequent pregnancy was notably lower in women with a history of cesarean scar defect (CSD), particularly among younger women (≤ 35 years). With rising rates of cesarean deliveries, concerns have emerged regarding a potential association between prior cesarean sections and reduced fertility. Several studies suggest that pregnancy intervals may lengthen, and subsequent conception rates may decline in these cases [ 20 , 21 ]. Wang et al. (2017) conducted a retrospective cohort study of 310 patients undergoing new IVF/ICSI cycles [ 14 ]. The authors found that patients with a previous Caesarean section (CS) had significantly lower implantation rates (24% vs. 35%; P < 0.05) and clinical pregnancy rates (40% vs. 54%; P < 0.05) compared to those with a prior vaginal delivery. There was an overall reduction in both biochemical and clinical pregnancy success rates. Additionally, the study reported significantly lower live birth rates in patients with a CS scar. The impact of a prior CS on frozen-thawed embryo transfer (FET) outcomes in freeze-all cycles was further examined in a more recent study by Huang et al. (2020) [ 22 ]. Their findings indicated that, compared to women with a previous vaginal birth, those with a prior CS had lower pregnancy rates and a higher risk of miscarriage. However, conflicting evidence exists. Zhang et al. (2016)'s retrospective analysis of 231 patients suggested that a prior cesarean scar had no significant effect on embryo implantation or IVF outcomes [ 23 ]. However, it is essential to acknowledge that these studies have limitations, including baseline variable imbalances and unadjusted confounders, which may have impacted the results. The live birth rate did not vary significantly between Groups I and II in our study. This suggests that the likelihood of achieving pregnancy during IVF cycles was not affected by the mere presence of a CS. Zhao et al. (2021) [ 10 ] conducted meta-analyses to assess the impact of previous CS on reproductive outcomes following assisted reproductive technology. The authors demonstrated that key gynaecological presentations like endometrial thickness, number of oocytes retrieved, implantation rate, ectopic pregnancy rate, preterm birth and stillbirth were similar between women with previous CS and women with previous VD. They concluded that cesarean sections harm clinical pregnancy rates and live birth rates. VDas opposed to repeat cesarean section, reduces the incidence of complications for both mother and baby. After adjusting for factors that may skew the results, however, it is still the case that CX25 / CS52 views show lower mean implantation rates than variational delivery vaginal deliveries (VDA). This pattern of results holds to the trend of Zhang et al.'s research for Cesarean Section: adverse effects on subsequent pregnancy outcomes [ 17 ]. Nonetheless, this study demonstrated that among women under 35 years old, the live birth rate decreased significantly with the presence of a scar niche compared to those with a prior vaginal delivery. Furthermore, in women with a niche, there was a reduction in favourable hCG test rates, mean implantation rates, and clinical pregnancy rates. Similar findings were reported by Diao et al. (2021), who showed that the presence of CSD in women, especially young women (age ≤ 35 years), significantly impairs the chances of subsequent pregnancy in patients undergoing IVF-ET [ 24 ]. The clinical pregnancy and live birth rates did not differ significantly between the CSD and VD groups in women aged over 35. Female age is a critical factor in IVF efficacy, as ovarian reserve declines, oocyte/embryo quality decreases, and embryonic aneuploidy rates increase with advanced maternal age (Cimadomo et al., 2018) [ 25 ]. It has been suggested that maternal age is the strongest predictor of live birth in IVF, overshadowing other factors like uterine pathology. Consequently, when evaluating the impact of IVF on childbirth outcomes, CSD has a lesser effect compared to advanced age. We also assessed the influence of visible fluid in the niche on embryo transfer outcomes. Compared to cases with no fluid in the niche cavity, the presence of fluid in the evident niche or endometrial cavity did not significantly impair implantation rates. Recent studies suggest that IVF birth rates remain unaffected by the mere presence of a cesarean scar, unless a scar defect (CSD) is present. However, women who undergo IVF after a cesarean delivery with a CSD may experience poorer pregnancy outcomes [ 26 , 27 ]. Moreover, our study found that the CSD group exhibited significantly reduced endometrial thickness on the trigger day, suggesting that CSD may impair implantation by adversely affecting endometrial receptivity. Limitations : This research focuses on how having a cesarean scar defect impacts the success of IVF-HZSI, but it is limited. The research design is a retrospective study, which raises the problem of possible selection bias and prevents a causal relationship from being established. Regardless of adjustments, other undetected factors–the quality of the surgically wielded instruments or even embryos themselves–may also have influenced our results. Scar defect classifications used a 2D transvaginal ultrasound without standardised criteria that impacted reproducibility. The focus of our follow-up research on immediate effects meant we neglected longer-term reproductive impacts. Lastly, this is a single-institution study, which limits its generalizability to other groups of people. In the future, more work using standardised assessments and collaboration among multiple centres will be indispensable for revealing whether these findings apply universally or not. Conclusion This study found that IVF/ICSI-ET success rates were not significantly affected by the presence of an intact Caesarean scar. However, a uterine niche (Caesarean scar defect, CSD) following a previous Caesarean section (CS) may negatively influence subsequent pregnancy outcomes. Notably, this adverse effect was more pronounced in younger women (< 35 years). In contrast, advanced maternal age (≥ 35 years) had a far greater impact on IVF success than CSD. We propose that the presence of a CSD, rather than a history of CS alone, may be the primary factor reducing conception rates in these women. Therefore, pre-IVF assessment for CSD should be considered to optimize treatment planning. To mitigate CS-related complications, promoting vaginal birth and reducing unnecessary primary Caesarean deliveries remain essential strategies. Abbreviations ASRM American Society for Reproductive Medicine BMI Body Mass Index CI Confidence Interval COH Controlled Ovarian Hyperstimulation CS Cesarean Section CSD Cesarean Scar Defect E2 Estradiol ET Embryo Transfer FET Frozen Embryo Transfer FSH Follicle Stimulating Hormone GnRH Gonadotropin-Releasing Hormone hCG Human Chorionic Gonadotropin ICSI Intracytoplasmic Sperm Injection IQR Interquartile Range IVF In Vitro Fertilization OR Odds Ratio SD Standard Deviation TVOR Transvaginal Oocyte Retrieval VD Vaginal Delivery WHO World Health Organization Declarations Ethics approval and consent to participate: This study was formally approved by the Ethics Committee of King Khalid University (ECM #2024-903) to ensure that it complied with international ethical standards. At the time of their hospital admission, all the patients who were enrolled signed an informed consent form, signalling that they agreed voluntarily to take part in the study after receiving a full explanation of its objectives, procedures, etc. The research conformed to principles of confidentiality, autonomy and beneficence. All data has been anonymised to protect the privacy of participants. These practices are entirely in line with the Declaration of Helsinki guidelines for ethical medical research as regards human subjects Consent to Publish declaration: not applicable. Availability of data and materials: The data that support the findings of this study are available from the corresponding author, upon reasonable request. Competing Interests: None declared Funding: This study was not funded. Authors' contributions: All the authors significantly contributed to this study. All authors reviewed and approved the final manuscript. F.A.Z conceived and designed the study and drafted the manuscript. S.K curated and analysed the data. R.A.Q conducted investigations and created visualizations. R.A.B provided resources and validation. H.A.R. managed project administration. S.A.A. supervised the research. M.E provided overall supervision and performed statistical analyses. S.M.Q. contributed to methodological development. S.M. conducted formal analyses. A.E. & L.Y.A validated the findings. E.M., L.Y.A & M.E provided overall supervision and secured funding. Acknowledgments: The authors gratefully acknowledge the clinical and technical staff for their support in data collection and patient care. We also extend our appreciation to the study participants for their contributions to this research. References Boerma T, Ronsmans C, Melesse DY, Barros AJD, Barros FC, Juan L, Moller AB, Say L, Hosseinpoor AR, Yi M, de Rabello Neto L, Temmerman D. Global epidemiology of use of and disparities in caesarean sections. Lancet. 2018;392(10155):1341–8. 10.1016/S0140-6736(18)31928-7 . Betran AP, Ye J, Moller AB, Souza JP, Zhang J. Trends and projections of caesarean section rates: global and regional estimates. BMJ Glob Health. 2021;6(6):e005671. 10.1136/bmjgh-2021-005671 . World Health Organization (WHO). (2015). WHO Statement on Caesarean Section Rates. Available at: https://www.who.int/publications/i/item/WHO-RHR-15.02 Wood R, Borodova A, Wolter S, N’Guessan M, Diallo AA, Diallo MK, Heldt K, Rocha C, Nabé I, Diané B, Cherif MS. Surgical site infections after caesarean section across sub-Sahara Africa: a scoping review of prevalence and associated factors. Front Global Women’s Health. 2025;6:1605049. https://doi.org/10.3389/fgwh.2025.1605049 . Chawanpaiboon S, Vogel JP, Moller AB, Lumbiganon P, Petzold M, Hogan D, Landoulsi S, Jampathong N, Kongwattanakul K, Laopaiboon M, Lewis C, Rattanakanokchai S, Teng DN, Thinkhamrop J, Watananirun K, Zhang J, Zhou W, Gülmezoglu AM. Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis. Lancet Glob Health. 2019;7(1):e37–46. 10.1016/S2214-109X(18)30451-0 . Molina G, Weiser TG, Lipsitz SR, Esquivel MM, Uribe-Leitz T, Azad T, Shah N, Semrau K, Berry WR, Gawande AA, Haynes AB. Relationship Between Cesarean Delivery Rate and Maternal and Neonatal Mortality. JAMA. 2015;314(21):2263–70. 10.1001/jama.2015.15553 . Miller ES, Hahn K, Grobman WA, Society for Maternal-Fetal Medicine Health Policy Committee. Consequences of a primary elective caesarean delivery across the reproductive life. Obstet Gynecol. 2013;121(4):789–97. Patounakis G, Ozcan MC, Chason RJ, Norian JM, Payson M, DeCherney AH, Yauger BJ. Impact of a prior cesarean delivery on embryo transfer: a prospective study. Fertil Steril. 2016;106(2):311–6. 10.1016/j.fertnstert.2016.03.045 . Mylonas I, Friese K. Indications for and risks of elective caesarean section. Dtsch Arztebl Int. 2015;112:489–95. Zhao J, Hao J, Xu B, Wang Y, Li Y. Impact of previous Caesarean section on reproductive outcomes after assisted reproductive technology: systematic review and meta-analyses. Reprod Biomed Online. 2021;43(2):197–204. 10.1016/j.rbmo.2021.04.007 . Cao D, Chen L. Effect of previous caesarean section on reproductive and pregnancy outcomes after assisted reproductive technology: A systematic review and metaanalysis. Experimental and Therapeutic Medicine. 2024;28(1):284. Zhao J, Hao J, Xu B, Wang Y, Li Y. Impact of previous Caesarean section on reproductive outcomes after assisted reproductive technology: systematic review and meta-analyses. Reproductive biomedicine online. 2021;43(2):197–204. https://doi.org/10.1016/j.rbmo.2021.04.007. Bulletti FM, Sciorio R, Conforti A, De Luca R, Bulletti C, Palagiano A, Berrettini M, Scaravelli G, Pierson RA. Causes of embryo implantation failure: A systematic review and metaanalysis of procedures to increase embryo implantation potential. Front Endocrinol. 2025;15:1429193. Wang YQ, Yin TL, Xu WM, Qi QR, Wang XC, Yang J. Reproductive outcomes in women with prior caesarean section undergoing in vitro fertilization: a retrospective case-control study. J Huazhong Univ Sci Technol Med Sci. 2017;37(6):922–7. Morlando M, Conte A, Schiattarella A. Reproductive outcome after cesarean scar pregnancy. Best Pract Res Clin Obstet Gynecol. 2023;91. doi.org/10.1016/j.bpobgyn.2023.102362 . Busnelli A, Levi-Setti PE, Inversetti A, Bignardi T, Vitagliano A, Dell’Acqua C, Zambella E, Simone ND. Investigating the impact of isthmocele and its surgical repair on fertility: results from a systematic review and meta-analysis. Reprod Biomed Online. 2024. doi.org/10.1016/j.rbmo.2024.104746 . Zhang Y, de Ziegler D, Hu X, Tai X, Han Y, Ma J, Zhang Y, Luo H. Previous caesarean delivery and the presence of caesarean scar defects could affect pregnancy outcomes after in vitro fertilization frozen-thawed embryo transfer: a retrospective cohort study. BMC Pregnancy Childbirth. 2022;22(1):769. 10.1186/s12884-022-05085-0 . Choksi A, Harnisch B, Honig S. What Every Provider Should Know About the 2020–2021 Updated AUA/ASRM Guidelines on Male Factor Infertility. Curr Sex Health Rep. 2022;14(2):31–8. https://doi.org/10.1007/s11930-022-00325-y . Zegers-Hochschild F, Adamson GD, Dyer S, Racowsky C, de Mouzon J, Sokol R, Rienzi L, Sunde A, Schmidt L, Cooke ID, Simpson JL, van der Poel S. The International Glossary on Infertility and Fertility Care, 2017. Hum Reprod. 2017;32(9):1786–801. 10.1093/humrep/dex234 . Smith GCS, Wood AM, Pell JP, Dobbie R. First caesarean birth and subsequent fertility. Fertil Steril. 2006;85:90–5. Tollanes MC, Melve KK, Irgens LM, Skjaerven R. Reduced fertility after caesarean delivery: a maternal choice. Obstet Gynecol. 2007;110:1256–63. Huang J, Lin J, Cai R, et al. Effect of a prior caesarean delivery on pregnancy outcomes of frozen-thawed embryo transfer: a retrospective cohort study in a freeze-all setting. Acta Obstet Gynecol Scand. 2020;99(10):1303–10. Chen N, Xu H, Wang Z, Sun B, Hu H. Pregnancy, delivery, and neonatal outcomes of in vitro fertilization-embryo transfer in patient with previous caesarean scar. Med Sci Monit. 2016;16(22):3288–95. Diao J, Gao G, Zhang Y, Wang X, Zhang Y, Han Y, et al. Caesarean section defects may affect pregnancy outcomes after in vitro fertilization-embryo transfer: a retrospective study. BMC Pregnancy Childbirth. 2021;21(1):487. Cimadomo D, Fabozzi G, Vaiarelli A, et al. Impact of maternal age on oocyte and embryo competence. Front Endocrinol (Lausanne). 2018;29(9):327. Tsuji S, Nobuta Y, Hanada T, Takebayashi A, Inatomi A, Takahashi A, Amano T, Murakami T. Prevalence, definition, and etiology of cesarean scar defect and treatment of cesarean scar disorder: A narrative review. Reproductive Med biology. 2023;22(1):e12532. https://doi.org/10.1002/rmb2.12532 . Donnez O. Cesarean scar defects: management of an iatrogenic pathology whose prevalence has dramatically increased. Fertil Steril. 2020;113(4):704–16. https://doi.org/10.1016/j.fertnstert.2020.01.037 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 30 Sep, 2025 Reviewers agreed at journal 15 Sep, 2025 Reviewers invited by journal 03 Sep, 2025 Editor invited by journal 05 Aug, 2025 Editor assigned by journal 01 Aug, 2025 Submission checks completed at journal 01 Aug, 2025 First submitted to journal 30 Jul, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Alarfaj","email":"","orcid":"","institution":"Medical intern, College of Medicine, Qassim university","correspondingAuthor":false,"prefix":"","firstName":"Suha","middleName":"A.","lastName":"Alarfaj","suffix":""},{"id":509490594,"identity":"0b53c567-b440-4732-9571-944e6fadc769","order_by":6,"name":"Mamdoh Eskandar","email":"","orcid":"","institution":"Department of Obstetrics and Gynecology, Reproductive Endocrinology and Infertility, King Khalid University","correspondingAuthor":false,"prefix":"","firstName":"Mamdoh","middleName":"","lastName":"Eskandar","suffix":""},{"id":509490595,"identity":"dca6f1d8-5fe4-4045-9cd2-e392a1f4aa96","order_by":7,"name":"Shazia Maqsood","email":"","orcid":"","institution":"Department of Obstetrics and Gynecology, Dr. Sulaiman Al Habib Medical Group","correspondingAuthor":false,"prefix":"","firstName":"Shazia","middleName":"","lastName":"Maqsood","suffix":""},{"id":509490596,"identity":"6d719ddc-21ce-440f-91c7-95afb452964d","order_by":8,"name":"Sajid Malik","email":"","orcid":"","institution":"Department of Zoology, of Human Genetics Program , Quaid-i-Azam University","correspondingAuthor":false,"prefix":"","firstName":"Sajid","middleName":"","lastName":"Malik","suffix":""},{"id":509490597,"identity":"0a427168-36f0-4431-b4d5-252b636aab01","order_by":9,"name":"Azza elzein","email":"","orcid":"","institution":"Department of Obstetrics and Gynecology, Dr. Sulaiman Al Habib Medical Group","correspondingAuthor":false,"prefix":"","firstName":"Azza","middleName":"","lastName":"elzein","suffix":""},{"id":509490599,"identity":"7bf935be-3921-4ace-927d-33230ee30904","order_by":10,"name":"Elhadi Miskeen","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIiWNgGAWjYBACAyA6ACQNQJwDHyqAJDNzA9FaGA/OOAPSwkhYC5RmYD7M2wZiE9Bizn5446EbBXXG/Oy9Bw7zzquN5m8HavlRsQ2nFsuetILDOQaHzSR7ziUcnLvteO6Mw4wNjD1nbuN22AGg+hyDAzYGN4Dk223HchuAWpgZ2/BoOf8GpKXOxv7+G4MDvHOO5c4nqOUG2BZmMwMJHoODvA01uRsIa3kG9ouxxJkcg4Mzjh3I3QjUchCvX84nb/6c86fOsL/9jPGHDzV1ufPOHz744EcFbi3o4DCYPEC0eiCoI0XxKBgFo2AUjBAAAEFbZiCc5jFkAAAAAElFTkSuQmCC","orcid":"","institution":"Medical intern, Department of Obstetrics and Gynecology, College of Medicine, University of Bisha","correspondingAuthor":true,"prefix":"","firstName":"Elhadi","middleName":"","lastName":"Miskeen","suffix":""},{"id":509490602,"identity":"38a3e795-3952-4408-a6aa-99103c2132ba","order_by":11,"name":"Laila Yahya Alhubaishi","email":"","orcid":"","institution":"Department of Obstetrics and Gynecology, College of Medicine and Health Sciences, Mohammed Bin Rashid University","correspondingAuthor":false,"prefix":"","firstName":"Laila","middleName":"Yahya","lastName":"Alhubaishi","suffix":""}],"badges":[],"createdAt":"2025-07-30 17:08:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7255223/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7255223/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":90944863,"identity":"ffa79463-3452-49f2-96e9-75e245242637","added_by":"auto","created_at":"2025-09-09 19:55:16","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1094611,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7255223/v1/b87c3037-3b6d-4125-9dfc-b445d16b6ac6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Impact of Previous Caesarean Delivery on IVF/ICSI Outcomes: A Retrospective Cohort Study on experience from Saudi Arabia","fulltext":[{"header":"1. INTRODUCTION","content":"\u003cp\u003eCesarean section (CS) is one of the most critical surgical procedures frequently indicated during the process of delivery for safeguarding either the mother, baby, or both, particularly in the presence of obstetric disorders and high-risk pregnancies. The criteria for CS include maternal conditions of hypertensive disorder, haemorrhage, obstructed labour, fetal distress, malpresentation and history of previous uterine scars [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe World Health Organisation (WHO) believes that the ideal Cesarean Section (CS) ratio for a population in general should lie within 10% and 15%. This range aims to balance the benefits to mothers and newborns, while minimising unnecessary surgical risks at the same time. But the world trend nowadays is a considerable distance from this recommendation [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eMany countries far exceed what they are supposed to be doing, placing global averages up around 20%.\u003c/p\u003e\u003cp\u003eIn several regions, CS rates have risen to a massive 40\u0026thinsp;~\u0026thinsp;50%, indicating an incommensurability with evidence-based obstetrics practice [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. This alarming increase makes it crucial to ask which medical, cultural, and socio-economic factors enable the abuse of surgical birth?\u003c/p\u003e\u003cp\u003eWhile CS can be life-saving, unnecessary procedures carry risks, including surgical complications, longer recovery times, and potential impacts on future pregnancies, including ectopic pregnancy, abnormal placentation, and uterine rupture [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. In more than 50% of women, CS leads to post-cesarean scar defects (PCSD) [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Women with previous CSs could be at an increased risk of secondary subfertility and irregular vaginal bleeding [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Evidence also supports that CS can affect the implantation potential of assisted reproductive technology (ART) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] and diminish the likelihood of embryo implantation [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] and cause pelvic pain [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe damaging effect of CS scar defect on childbirth outcome has been given more attention to currently. Several studies have found that CS scar defects can impede embryo implantation and lower the likelihood of conception after in vitro fertilization and embryo transfer (IVF-ET) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Not with standing these findings, little is known about the mechanism through which CS scar defects disrupt the progression of pregnancy. There is uncertainty as to whether the anatomical changes imply uterine malfunction, which could limit the likelihood of optimal fertility, or if they genuinely impede the placement of embryos. Despite this fact, controversy over the therapeutic benefit of Caesarean section (CS) in women undergoing in vitro fertilization and embryo transfer (IVF\u0026ndash;ET) continues today. Some studies indicate that CS defects may impair endometrial receptivity and embryo implantation, eventually leading to reduced IVF success rates [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e], while other research shows no statistically significant differences between clinical pregnancy or live birth rates compared with control women who have never had CS [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].In this context, this study therefore evaluates the impact of VD, CS without a scar defect (CSD), and with a scar defect (CSD) on IVF/ICSI outcomes.\u003c/p\u003e"},{"header":"2. MATERIALS AND METHODS","content":"\u003cp\u003e\u003cstrong\u003eStudy design\u003c/strong\u003e\u003cp\u003eThis retrospective cross-sectional study was conducted between 2019 and 2023. The sample size was estimated by the rate of CS delivery using stratified analogous random sampling strategies with a 95% confidence interval. The hospital's electronic health records were utilized to assess the eligibility of the participants. This study included women between 20 and 40 years of age with secondary subfertility who had successful pregnancy(s) in the past and were treated either with a long mid-luteal GnRH agonist or a short GnRH antagonist protocol for IVF/ICSI stimulation. Women above 40 years were omitted. Similarly, women with morbidities including adenomyosis, intrauterine adhesion, uterine fibroids, congenital or acquired uterine malformations, parental chromosomal abnormalities, a history of recurrent spontaneous abortion, or a history of myomectomy or endometrioma resection were excluded.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eStudy population\u003c/b\u003e: A total of 2,284 women fulfilled the eligibility requirements. Women were divided into three groups based on the mode of previous delivery and the occurrence of CS: Group I: Vaginal delivery (VD; n\u0026thinsp;=\u0026thinsp;1,109); Group II: Previous delivery by CS but with no scar defect (CS; n\u0026thinsp;=\u0026thinsp;742); and Group III: Previous CS with scar defect (CSD; n\u0026thinsp;=\u0026thinsp;433). The participants were further stratified into age categories: \u0026le;35 years and \u0026gt;\u0026thinsp;35 years. Patients in Group III were subdivided into: Group IIIa (n\u0026thinsp;=\u0026thinsp;261): no fluid in the endometrial cavity; Group IIIb (n\u0026thinsp;=\u0026thinsp;172): presence of fluid in the endometrial cavity.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eDiagnostic and Treatment Protocols\u003c/strong\u003e\u003cp\u003eCSD was evaluated and classified by competent sonographers using two-dimensional transvaginal ultrasonography. Patients underwent controlled ovarian hyperstimulation (COH) for the IVF/ICSI cycle (Vervoort et al., 2018). Serial blood tests for serum oestradiol concentration and transvaginal ultrasound scans were performed for all patients during the IVF stimulation phase. Ultrasound findings were collected on endometrial thickness, whether there was fluid in the uterine cavity, and the number and size of ovarian follicles.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eParticipants underwent transvaginal oocyte retrieval (TVOR) 36 hours after the human chorionic gonadotropin (hCG) injection, per ASRM\u003c/p\u003e\u003cp\u003eguidelines (2022) [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Embryos were transferred on day 3. In general, two embryos were transferred; however, in a few exceptional cases, three embryos were transferred, particularly when the patient was of advanced maternal age or had low-quality embryos. On days two or three following TVOR, patients were administered luteal support with progesterone. The IVF unit team collected details on the outcome of the IVF treatment cycle through follow-up calls with the patients. The live birth rate served as the primary outcome measure (Zegers-Hochschild et al., 2017) [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Positive hCG tests, clinical pregnancies, mean implantation rates, miscarriages, ectopic pregnancies, mode of delivery, and gestational age at birth were recorded.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eData collection\u003c/strong\u003e\u003cp\u003eIn this study, data were obtained from comprehensive reviews of electronic medical records, ultrasound reports, and structured interviews with patients who returned for follow-up. Baseline demographic information and clinical characteristics\u0026mdash;including age, BMI, period of infertility, and obstetric history\u0026mdash;were extracted from hospital records. Information on detailed IVF/ICSI cycle parameters, including stimulation protocols, doses of gonadotropins, endometrial thickness and follicular measurements, was retrieved from electronic health records and laboratory reports. Cesarean scar defects were assessed and graded by two independent sonographers with a standardised 2D transvaginal ultrasound imaging system. When were levels of serum estradiol and hCG test results obtained? Pregnancy outcomes, such as clinical confirmation of pregnancy, live birth, miscarriage and ectopic pregnancy, were confirmed through follow-up telephone interviews with the IVF clinical team. Postpartum medical records were examined for additional details of delivery\u0026mdash;such as gestational age, birth weight and mode.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eTo ensure the accuracy of our data, we used uniform extraction forms, and any discrepancies in data were solved by cross-referencing original clinical records.\u003c/p\u003e\u003cp\u003e\u003cb\u003eStatistical Analysis\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAll data were maintained in MS-Excel, and analyses were carried out through GraphPad Prism (Ver. 5) and STATA (Ver. 11). Descriptive analyses were conducted, and the baseline characteristics across the three groups were compared using the SNK-q test, Pearson's χ2 test, ANOVA and the Kruskal-Wallis H test. Logistic and linear regressions were calculated.\u003c/p\u003e"},{"header":"3. RESULTS","content":"\u003cp\u003eA total of 2,284 participants were included in the study, categorized into three groups: Group I (n\u0026thinsp;=\u0026thinsp;1,109), Group II (n\u0026thinsp;=\u0026thinsp;742), and Group III (n\u0026thinsp;=\u0026thinsp;433) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Baseline clinical parameters, including infertility aetiology, infertility type, stimulation protocols, and fertilisation method, did not differ significantly among the groups, suggesting that the presence of a cesarean scar did not affect early embryogenesis or fertilisation outcomes. All groups had similar rates of fertilization and number of embryos transferred. The groups did differ in some more critical respects. Compared with any of the three groups, the number of high-quality embryos for transplantation differed significantly (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The endometrial thickness on the day of the procedure was also strikingly thinner in Group III than in Groups I and II (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Moreover, Day 2 embryo transfers were proportionately greater in Group III than in the other two groups (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). All three groups were broadly comparable in terms of baseline conditions and treatment parameters. In terms of age, BMI, and ovarian stimulation outcomes, no significant differences were seen among the three groups.\u003c/p\u003e\u003cp\u003eThe proportion of fertilized oocytes was likewise not significantly different (P\u0026thinsp;\u0026gt;\u0026thinsp;1.05, NS: not statistically significant), thoughthey did show some variation between groups I and III (P\"*\u0026lt;0.01). However, compared to Groups I and III, endometrial thickness was \"significantly\" smaller in Group II (0.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1 cm) (P\u0026thinsp;=\u0026thinsp;0.032). Notably, Group III (CS with a scar defect) demonstrated distinct embryological patterns, including a higher proportion of Day 3 transfers (90.3% vs. 79.9\u0026ndash;83.3%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.005) and a significantly lower number of excellent quality embryos transferred (P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001).\u003c/p\u003e\u003cp\u003eThese variations in endometrial characteristics and embryo quality metrics could be responsible for the differences in reproductive outcomes seen between treatment groups.\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\u003eSample characteristics, clinical presentation and treatment modalities in three groups\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\u003eVariable / Group#\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSample size (N)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1109\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e742\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e433\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\u003eAge (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e34.5\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e35.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.68\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInfertility duration (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.2\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.048\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eInfertility cause, N (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTubal factor\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e485 (43.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e436 (58.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e168 (38.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\" morerows=\"4\" rowspan=\"5\"\u003e\u003cp\u003e0.305\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOvary factor\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e156 (14.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e89 (11.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e62 (14.3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale factor\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e180 (16.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e67 (9.02)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e53 (12.2)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUnexplained\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e82 (7.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e53 (7.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e48 (11.0)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCombined\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e206 (18.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e97 (13.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e102 (23.5)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eInfertility category, N (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrimary\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e108 (9.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e39 (5.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e29 (6.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.668\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSecondary\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1001 (90.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e703 (94.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e404 (93.3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e24.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e23.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e22.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.802\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBasal FSH (IU/L)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.1\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.98\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.188\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eStimulation protocol, N (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMd-luteal (Triptorelin)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e667 (60.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e599 (80.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e293 (67.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.887\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAntagonist (Cetrorelix)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e442 (39.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e143 (19.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e140 (32.3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal gonadotropins (IU)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2889\u0026thinsp;\u0026plusmn;\u0026thinsp;761\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2812\u0026thinsp;\u0026plusmn;\u0026thinsp;669\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2800\u0026thinsp;\u0026plusmn;\u0026thinsp;673\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.799\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDuration of stimulation (days)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e8.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.818\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eE2 level at event day (ng/mL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.978\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eThickness of endometrium (cm) at event day\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.89\u0026thinsp;\u0026plusmn;\u0026thinsp;.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.80\u0026thinsp;\u0026plusmn;\u0026thinsp;.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.032\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFollicle number with a diameter\u0026thinsp;\u0026ge;\u0026thinsp;1.4 (cm) at event day\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.422\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRetrieved oocytes (N)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11.1\u0026thinsp;\u0026plusmn;\u0026thinsp;6.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10.1\u0026thinsp;\u0026plusmn;\u0026thinsp;6.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.290\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eFertilization methods, N (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIVF\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e832 (75.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e558 (75.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e298 (68.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.712\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eICSI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e277 (25.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e184 (24.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e135 (31.1)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFertilization rate (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e79.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e73.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e79.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.923\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCleavage rate (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e98.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e98.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e98.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.710\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAvailable embryos (N)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4(2,6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (2,6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3 (2,6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.632\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eExcellent quality embryos (N)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (1,4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (1,4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2 (1,4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.561\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of embryos injected (N)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (1,2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1,2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1 (1,2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.090\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDay of Transfer, N (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eD2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e185 (16.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e149 (20.08)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e42 (9.69)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eD3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e924 (83.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e593 (79.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e391 (90.3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eExcellent quality embryo transplanted (N)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (1,2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1,1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1 (1,1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e#, variables assessed before delivery; values in % or mean\u0026thinsp;\u0026plusmn;\u0026thinsp;St.Dev\u003c/p\u003e\u003cp\u003eCrude and adjusted ORs were assessed throughout, considering covariates such as age, infertility factors, body mass index (BMI), endometrial thickness on the trigger day, fertilization. fertilization method, number of transferred embryos, number of high-quality embryos transferred, and day of transfer (see Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), the differences in pregnancy outcome between Group I and Group II. Group III exhibited a significantly lower live birth rate compared to Group I (adjusted OR: 0.53), which was not significant. Even in unadjusted analyses, Group III had reduced rates of clinical pregnancy and positive hCG tests (crude OR: 0.49 and 0.53, respectively). The mean implantation rate in Group III was substantially lower than in Group I after adjusting for confounders (adjusted OR: 0.88). Early abortion and ectopic pregnancy rates did not differ significantly between Group III and Group I.\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\u003eComparison of pregnancy outcome in three groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables/ groups\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e% (n/N)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eCrude OR\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdjusted OR\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLive Births\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e57% (631/1109)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e42% (308/742)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.92 (0.78\u0026ndash;1.09)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.98 (0.83\u0026ndash;1.17)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e39% (170/433)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.41 (0.34\u0026ndash;0.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.53 (0.42\u0026ndash;0.66)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePositive hCG Test\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54% (599/1109)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55% (411/742)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.10 (0.94\u0026ndash;1.29)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.48 (1.23\u0026ndash;1.78)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23% (99/433)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.53 (0.43\u0026ndash;0.66)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.73 (0.59\u0026ndash;0.91)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eClinical Pregnancy\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e63% (703/1109)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e70% (521/742)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.99 (0.85\u0026ndash;1.15)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.25 (1.06\u0026ndash;1.48)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e28% (121/433)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.49 (0.39\u0026ndash;0.61)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.62 (0.49\u0026ndash;0.79)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean Implantation rate#\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.98 (0.84\u0026ndash;1.13)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.96 (0.82\u0026ndash;1.11)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.89 (0.75\u0026ndash;1.06)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.88 (0.72\u0026ndash;1.07)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eEarly Abortion\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11% (123/1109)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14% (101/742)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.43 (1.08\u0026ndash;1.88)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.69 (1.25\u0026ndash;2.29)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e18% (78/433)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.97 (0.73\u0026ndash;1.30)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.33 (0.95\u0026ndash;1.85)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eEctopic Pregnancy\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.3% (25/1109)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.8% (21/742)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.43 (0.78\u0026ndash;2.62)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.94 (1.00\u0026ndash;3.76)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.3% (19/433)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.96 (0.51\u0026ndash;1.83)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.83 (0.96\u0026ndash;3.50)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e#, mean, St.Dev\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Pregnancy outcome in age stratified participants groups as depicted through binary logistic regression. In participants\u0026thinsp;\u0026lt;\u0026thinsp;35 years, Group III (CS with scar defect) demonstrated significantly worse reproductive outcomes compared to Group I (vaginal delivery), including a 55% reduction in live birth rates (adjusted OR 0.27, *p*\u0026lt;0.001), 42% lower clinical pregnancy rates (adjusted OR 0.58, *p*\u0026lt;0.001), and a 3-fold increased risk of ectopic pregnancy (adjusted OR 3.01, *p*=0.001). In contrast, Group II (CS without defect) showed comparable outcomes to Group I in this age category.\u003c/p\u003e\u003cp\u003eIn women over the age of 35, live birth rates and clinical pregnancy rates were comparable at specific points between groups, regardless of age. However, those in Group II showed higher biochemical pregnancy rates(adjusted OR 1.73, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). This group also had a higher incidence of early abortion(adjusted OR 2.08, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). This suggests that cesarean section and age may interact.\u003c/p\u003e\u003cp\u003eThese findings highlight that CS scar defects disproportionately impair fertility outcomes in younger women, while advanced maternal age (\u0026gt;\u0026thinsp;35 years) may overshadow the impact of uterine scarring on IVF success .\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\u003ePregnancy outcome in age stratified participants groups as depicted through binary logistic regression\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\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\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables/ groups\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;35 years\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;35 years\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\u003e% (n/N)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eCrude OR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdjusted OR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e% (n/N)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eCrude OR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eAdjusted OR\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLive Births\u003c/b\u003e\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\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54% (306/566)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e26% (141/543)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e47% (180/383)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.66 (0.53\u0026ndash;0.83)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.93 (0.73\u0026ndash;1.18)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e31% (111/359)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.99 (0.76\u0026ndash;1.29)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.98 (0.73\u0026ndash;1.30)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32% (70/219)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.26 (0.19\u0026ndash;0.35)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.27 (0.18\u0026ndash;0.41)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e32% (69/214)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.83 (0.59\u0026ndash;1.16)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.91 (0.63\u0026ndash;1.30)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePositive hCG Test\u003c/b\u003e\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\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e58% (326/566)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e45% (243/543)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50% (191/383)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.71 (0.58\u0026ndash;0.88)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.76 (0.61\u0026ndash;0.95)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e53% (190/359)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.53 (1.21\u0026ndash;1.94)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.73 (1.34\u0026ndash;2.22)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32% (69/219)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.36 (0.26\u0026ndash;0.49)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.58 (0.41\u0026ndash;0.82)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e26% (56/214)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.69 (0.50\u0026ndash;0.95)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.02 (0.74\u0026ndash;1.41)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eClinical Pregnancy\u003c/b\u003e\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\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e59% (366/566)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e41% (222/543)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e53% (202/383)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.71 (0.58\u0026ndash;0.88)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.76 (0.61\u0026ndash;0.95)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e56% (201/359)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.53 (1.22\u0026ndash;1.93)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.61 (1.28\u0026ndash;2.02)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e38% (83/219)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.36 (0.27\u0026ndash;0.48)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.58 (0.42\u0026ndash;0.81)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e29% (63/214)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.72 (0.52\u0026ndash;0.99)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.94 (0.68\u0026ndash;1.30)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean Implantation rate#\u003c/b\u003e\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\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.21 (0.96\u0026ndash;1.52)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.22 (0.97\u0026ndash;1.54)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.01 (0.78\u0026ndash;1.32)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.03 (0.78\u0026ndash;1.35)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eEarly Abortion\u003c/b\u003e\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\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10 (56/566)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e21 (116/543)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10 (39/383)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.91 (0.63\u0026ndash;1.31)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.06 (0.72\u0026ndash;1.55)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e32 (115/359)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.01 (1.43\u0026ndash;2.82)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e2.08 (1.45\u0026ndash;2.98)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e16 (36/219)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.01 (0.66\u0026ndash;1.54)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.06 (0.68\u0026ndash;1.66)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e22 (47/214)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.93 (0.62\u0026ndash;1.39)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.41 (0.89\u0026ndash;2.21)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eEctopic Pregnancy\u003c/b\u003e\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\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.98 (11/566)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eRef.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.2 (17/543)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.2 (8/383)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.81 (0.37\u0026ndash;1.77)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.21 (0.53\u0026ndash;2.78)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e6.3 (22/359)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.18 (1.05\u0026ndash;4.55)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e2.21 (1.03\u0026ndash;4.71)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8.9 (19/219)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.83 (0.95\u0026ndash;3.52)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.01 (1.52\u0026ndash;5.97)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eNA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eNA\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e#, mean\u0026thinsp;\u0026plusmn;\u0026thinsp;St.Dev.\u003c/p\u003e\u003cp\u003eTo observe the effect of fluid in the endometrial cavity, participants in Group III were subdivided into two groups, and their pregnancy outcomes were assessed (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Impact of Endometrial Cavity Fluid in Women with Cesarean Scar Defects\u003c/p\u003e\u003cp\u003eSubgroup analysis of Group III (CS scar defect) compared women with (IIIa, *n*=261) and without (IIIb, *n*=172) endometrial cavity fluid. After adjusting for confounders, no statistically significant differences were observed in live birth rates (adjusted OR 1.11), clinical pregnancy (adjusted OR 1.03), or positive hCG tests (adjusted OR 0.81). While IIIa exhibited numerically higher implantation rates (0.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36 vs. 0.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36), this did not translate to improved clinical outcomes. Complications (early abortion, ectopic pregnancy) were rare and did not differ meaningfully between subgroups.\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\u003eSubgroup analysis of the respondents with or without fluid in the endometrial cavity\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=\"char\" char=\".\" 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\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSubgroup IIIa\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;261)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSubgroup IIIb\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;172)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eCrude OR\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eAdjusted OR\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLive Birth\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32% (83/261)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24% (41/172)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePositive hCG Test\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e42% (109/261)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31% (53/172)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.81\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eClinical Pregnancy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e36% (94/261)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e28% (48/172)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.73\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1.03\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean Implantation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36\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\u003eEarly Abortion\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\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\u003eEctopic Pregnancy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\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\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e presents the delivery success and newborn health outcomes of the three groups that complied with IVF/ICSI-ET. The analysis of delivery modes revealed striking differences among groups. Women with prior vaginal deliveries (Group I) had significantly lower cesarean rates (56%) compared to those with previous cesarean sections (Groups II and III: 96\u0026ndash;97%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Neonatal outcomes showed clinically significant trends, though not all reached statistical significance. Most notably, the cesarean scar defect group (Group III) demonstrated concerning patterns, including a substantially higher preterm birth rate (40% vs. 10\u0026ndash;15% in other groups, p\u0026thinsp;=\u0026thinsp;0.089) and a markedly lower full-term delivery rate (55% vs. 94\u0026ndash;97%, p\u0026thinsp;=\u0026thinsp;0.091). Twin births were most common in Group I (26%) and virtually absent in Group III (0%). Birth weights (3.13\u0026ndash;3.27 kg) and low birth weight rates (6\u0026ndash;12%) were comparable across all groups (p\u0026thinsp;\u0026gt;\u0026thinsp;0.2).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eChildbirth and neonatal conditions after embryo transfer\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\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGroup I\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGroup II\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eGroup III\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCaesarean birth rate (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56% (353/631)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e97% (298/308)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e96% (163/170)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTwin birth rate (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e26% (164/631)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8% (26/308)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFull term birth rate (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e94% (591/631)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e97% (297/308)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e55% (93/170\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.091\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre-term birth rate (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15% (93/631)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10% (31/308)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e40% (68/170)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.089\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBirth weight (Kgs)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.27\u0026thinsp;\u0026plusmn;\u0026thinsp;.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.22 \u0026plusmn;. 60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.13\u0026thinsp;\u0026plusmn;\u0026thinsp;.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.213\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLow weight birth rate (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12% (73/631)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9% (29/308)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6% (11/170)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.533\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"4. DISCUSSION","content":"\u003cp\u003eThis retrospective analysis, based on the large sample of IVF/ICSI-ET, found no significant differences in pregnancy outcomes between women in Groups I and II. However, the likelihood of subsequent pregnancy was notably lower in women with a history of cesarean scar defect (CSD), particularly among younger women (\u0026le;\u0026thinsp;35 years). With rising rates of cesarean deliveries, concerns have emerged regarding a potential association between prior cesarean sections and reduced fertility. Several studies suggest that pregnancy intervals may lengthen, and subsequent conception rates may decline in these cases [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eWang et al. (2017) conducted a retrospective cohort study of 310 patients undergoing new IVF/ICSI cycles [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The authors found that patients with a previous Caesarean section (CS) had significantly lower implantation rates (24% vs. 35%; P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) and clinical pregnancy rates (40% vs. 54%; P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) compared to those with a prior vaginal delivery. There was an overall reduction in both biochemical and clinical pregnancy success rates. Additionally, the study reported significantly lower live birth rates in patients with a CS scar.\u003c/p\u003e\u003cp\u003eThe impact of a prior CS on frozen-thawed embryo transfer (FET) outcomes in freeze-all cycles was further examined in a more recent study by Huang et al. (2020) [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Their findings indicated that, compared to women with a previous vaginal birth, those with a prior CS had lower pregnancy rates and a higher risk of miscarriage. However, conflicting evidence exists. Zhang et al. (2016)'s retrospective analysis of 231 patients suggested that a prior cesarean scar had no significant effect on embryo implantation or IVF outcomes [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. However, it is essential to acknowledge that these studies have limitations, including baseline variable imbalances and unadjusted confounders, which may have impacted the results.\u003c/p\u003e\u003cp\u003eThe live birth rate did not vary significantly between Groups I and II in our study. This suggests that the likelihood of achieving pregnancy during IVF cycles was not affected by the mere presence of a CS. Zhao et al. (2021) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] conducted meta-analyses to assess the impact of previous CS on reproductive outcomes following assisted reproductive technology. The authors demonstrated that key gynaecological presentations like endometrial thickness, number of oocytes retrieved, implantation rate, ectopic pregnancy rate, preterm birth and stillbirth were similar between women with previous CS and women with previous VD. They concluded that cesarean sections harm clinical pregnancy rates and live birth rates.\u003c/p\u003e\u003cp\u003eVDas opposed to repeat cesarean section, reduces the incidence of complications for both mother and baby. After adjusting for factors that may skew the results, however, it is still the case that CX25 / CS52 views show lower mean implantation rates than variational delivery vaginal deliveries (VDA). This pattern of results holds to the trend of Zhang et al.'s research for Cesarean Section: adverse effects on subsequent pregnancy outcomes [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eNonetheless, this study demonstrated that among women under 35 years old, the live birth rate decreased significantly with the presence of a scar niche compared to those with a prior vaginal delivery. Furthermore, in women with a niche, there was a reduction in favourable hCG test rates, mean implantation rates, and clinical pregnancy rates. Similar findings were reported by Diao et al. (2021), who showed that the presence of CSD in women, especially young women (age\u0026thinsp;\u0026le;\u0026thinsp;35 years), significantly impairs the chances of subsequent pregnancy in patients undergoing IVF-ET [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. The clinical pregnancy and live birth rates did not differ significantly between the CSD and VD groups in women aged over 35. Female age is a critical factor in IVF efficacy, as ovarian reserve declines, oocyte/embryo quality decreases, and embryonic aneuploidy rates increase with advanced maternal age (Cimadomo et al., 2018) [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. It has been suggested that maternal age is the strongest predictor of live birth in IVF, overshadowing other factors like uterine pathology. Consequently, when evaluating the impact of IVF on childbirth outcomes, CSD has a lesser effect compared to advanced age. We also assessed the influence of visible fluid in the niche on embryo transfer outcomes. Compared to cases with no fluid in the niche cavity, the presence of fluid in the evident niche or endometrial cavity did not significantly impair implantation rates.\u003c/p\u003e\u003cp\u003eRecent studies suggest that IVF birth rates remain unaffected by the mere presence of a cesarean scar, unless a scar defect (CSD) is present. However, women who undergo IVF after a cesarean delivery with a CSD may experience poorer pregnancy outcomes [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Moreover, our study found that the CSD group exhibited significantly reduced endometrial thickness on the trigger day, suggesting that CSD may impair implantation by adversely affecting endometrial receptivity.\u003c/p\u003e\u003cp\u003e\u003cb\u003eLimitations\u003c/b\u003e:\u003c/p\u003e\u003cp\u003eThis research focuses on how having a cesarean scar defect impacts the success of IVF-HZSI, but it is limited. The research design is a retrospective study, which raises the problem of possible selection bias and prevents a causal relationship from being established.\u003c/p\u003e\u003cp\u003eRegardless of adjustments, other undetected factors\u0026ndash;the quality of the surgically wielded instruments or even embryos themselves\u0026ndash;may also have influenced our results. Scar defect classifications used a 2D transvaginal ultrasound without standardised criteria that impacted reproducibility. The focus of our follow-up research on immediate effects meant we neglected longer-term reproductive impacts.\u003c/p\u003e\u003cp\u003eLastly, this is a single-institution study, which limits its generalizability to other groups of people.\u003c/p\u003e\u003cp\u003eIn the future, more work using standardised assessments and collaboration among multiple centres will be indispensable for revealing whether these findings apply universally or not.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study found that IVF/ICSI-ET success rates were not significantly affected by the presence of an intact Caesarean scar. However, a uterine niche (Caesarean scar defect, CSD) following a previous Caesarean section (CS) may negatively influence subsequent pregnancy outcomes. Notably, this adverse effect was more pronounced in younger women (\u0026lt;\u0026thinsp;35 years). In contrast, advanced maternal age (\u0026ge;\u0026thinsp;35 years) had a far greater impact on IVF success than CSD. We propose that the presence of a CSD, rather than a history of CS alone, may be the primary factor reducing conception rates in these women. Therefore, pre-IVF assessment for CSD should be considered to optimize treatment planning. To mitigate CS-related complications, promoting vaginal birth and reducing unnecessary primary Caesarean deliveries remain essential strategies.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eASRM\u0026nbsp;\u0026nbsp; \u0026nbsp;\u0026nbsp; American Society for Reproductive Medicine\u003c/p\u003e\n\u003cp\u003eBMI\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Body Mass Index\u003c/p\u003e\n\u003cp\u003eCI\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Confidence Interval\u003c/p\u003e\n\u003cp\u003eCOH\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; Controlled Ovarian Hyperstimulation\u003c/p\u003e\n\u003cp\u003eCS\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Cesarean Section\u003c/p\u003e\n\u003cp\u003eCSD\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Cesarean Scar Defect\u003c/p\u003e\n\u003cp\u003eE2\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Estradiol\u003c/p\u003e\n\u003cp\u003eET\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Embryo Transfer\u003c/p\u003e\n\u003cp\u003eFET\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Frozen Embryo Transfer\u003c/p\u003e\n\u003cp\u003eFSH\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Follicle Stimulating Hormone\u003c/p\u003e\n\u003cp\u003eGnRH\u0026nbsp;\u0026nbsp; \u0026nbsp;\u0026nbsp;Gonadotropin-Releasing Hormone\u003c/p\u003e\n\u003cp\u003ehCG\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Human Chorionic Gonadotropin\u003c/p\u003e\n\u003cp\u003eICSI\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Intracytoplasmic Sperm Injection\u003c/p\u003e\n\u003cp\u003eIQR\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Interquartile Range\u003c/p\u003e\n\u003cp\u003eIVF\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;In Vitro Fertilization\u003c/p\u003e\n\u003cp\u003eOR\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Odds Ratio\u003c/p\u003e\n\u003cp\u003eSD\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Standard Deviation\u003c/p\u003e\n\u003cp\u003eTVOR\u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp;Transvaginal Oocyte Retrieval\u003c/p\u003e\n\u003cp\u003eVD \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Vaginal Delivery\u003c/p\u003e\n\u003cp\u003eWHO \u0026nbsp; \u0026nbsp; \u0026nbsp;World Health Organization\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u0026nbsp;\u003c/strong\u003eThis study was formally approved by the Ethics Committee of King Khalid University (ECM #2024-903) to ensure that it complied with international ethical standards.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAt the time of their hospital admission, all the patients who were enrolled signed an informed consent form, signalling that they agreed voluntarily to take part in the study after receiving a full explanation of its objectives, procedures, etc.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe research conformed to principles of confidentiality, autonomy and beneficence. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll data has been anonymised to protect the privacy of participants. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThese\u0026nbsp;practices\u0026nbsp;are\u0026nbsp;entirely\u0026nbsp;in\u0026nbsp;line with the Declaration of Helsinki guidelines for ethical medical research\u0026nbsp;as\u0026nbsp;regards\u0026nbsp;human subjects\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Publish declaration:\u0026nbsp;\u003c/strong\u003enot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u0026nbsp;\u003c/strong\u003eThe data that support the findings of this study are available from the corresponding author, upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests:\u003c/strong\u003e None declared\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e This study was not funded.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions:\u0026nbsp;\u003c/strong\u003eAll the authors significantly contributed to this study. All authors reviewed and approved the final manuscript.\u0026nbsp;F.A.Z conceived and designed the study and drafted the manuscript. S.K curated and analysed the data. R.A.Q conducted investigations and created visualizations. R.A.B provided resources and validation. H.A.R. managed project administration. S.A.A. supervised the research. M.E provided overall supervision and performed statistical analyses. S.M.Q. contributed to methodological development. S.M. conducted formal analyses. A.E. \u0026amp; L.Y.A validated the findings. E.M., L.Y.A \u0026amp; M.E provided overall supervision and secured funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u0026nbsp;\u003c/strong\u003eThe authors gratefully acknowledge the clinical and technical staff for their support in data collection and patient care. We also extend our appreciation to the study participants for their contributions to this research.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBoerma T, Ronsmans C, Melesse DY, Barros AJD, Barros FC, Juan L, Moller AB, Say L, Hosseinpoor AR, Yi M, de Rabello Neto L, Temmerman D. Global epidemiology of use of and disparities in caesarean sections. Lancet. 2018;392(10155):1341\u0026ndash;8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0140-6736(18)31928-7\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(18)31928-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBetran AP, Ye J, Moller AB, Souza JP, Zhang J. Trends and projections of caesarean section rates: global and regional estimates. BMJ Glob Health. 2021;6(6):e005671. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/bmjgh-2021-005671\u003c/span\u003e\u003cspan address=\"10.1136/bmjgh-2021-005671\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWorld Health Organization (WHO). (2015). WHO Statement on Caesarean Section Rates. Available at: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.who.int/publications/i/item/WHO-RHR-15.02\u003c/span\u003e\u003cspan address=\"https://www.who.int/publications/i/item/WHO-RHR-15.02\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWood R, Borodova A, Wolter S, N\u0026rsquo;Guessan M, Diallo AA, Diallo MK, Heldt K, Rocha C, Nab\u0026eacute; I, Dian\u0026eacute; B, Cherif MS. Surgical site infections after caesarean section across sub-Sahara Africa: a scoping review of prevalence and associated factors. Front Global Women\u0026rsquo;s Health. 2025;6:1605049. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fgwh.2025.1605049\u003c/span\u003e\u003cspan address=\"10.3389/fgwh.2025.1605049\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChawanpaiboon S, Vogel JP, Moller AB, Lumbiganon P, Petzold M, Hogan D, Landoulsi S, Jampathong N, Kongwattanakul K, Laopaiboon M, Lewis C, Rattanakanokchai S, Teng DN, Thinkhamrop J, Watananirun K, Zhang J, Zhou W, G\u0026uuml;lmezoglu AM. Global, regional, and national estimates of levels of preterm birth in 2014: a systematic review and modelling analysis. Lancet Glob Health. 2019;7(1):e37\u0026ndash;46. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S2214-109X(18)30451-0\u003c/span\u003e\u003cspan address=\"10.1016/S2214-109X(18)30451-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMolina G, Weiser TG, Lipsitz SR, Esquivel MM, Uribe-Leitz T, Azad T, Shah N, Semrau K, Berry WR, Gawande AA, Haynes AB. Relationship Between Cesarean Delivery Rate and Maternal and Neonatal Mortality. JAMA. 2015;314(21):2263\u0026ndash;70. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/jama.2015.15553\u003c/span\u003e\u003cspan address=\"10.1001/jama.2015.15553\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMiller ES, Hahn K, Grobman WA, Society for Maternal-Fetal Medicine Health Policy Committee. Consequences of a primary elective caesarean delivery across the reproductive life. Obstet Gynecol. 2013;121(4):789\u0026ndash;97.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePatounakis G, Ozcan MC, Chason RJ, Norian JM, Payson M, DeCherney AH, Yauger BJ. Impact of a prior cesarean delivery on embryo transfer: a prospective study. Fertil Steril. 2016;106(2):311\u0026ndash;6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.fertnstert.2016.03.045\u003c/span\u003e\u003cspan address=\"10.1016/j.fertnstert.2016.03.045\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMylonas I, Friese K. Indications for and risks of elective caesarean section. Dtsch Arztebl Int. 2015;112:489\u0026ndash;95.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhao J, Hao J, Xu B, Wang Y, Li Y. Impact of previous Caesarean section on reproductive outcomes after assisted reproductive technology: systematic review and meta-analyses. Reprod Biomed Online. 2021;43(2):197\u0026ndash;204. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.rbmo.2021.04.007\u003c/span\u003e\u003cspan address=\"10.1016/j.rbmo.2021.04.007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCao D, Chen L. Effect of previous caesarean section on reproductive and pregnancy outcomes after assisted reproductive technology: A systematic review and metaanalysis. Experimental and Therapeutic Medicine. 2024;28(1):284.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhao J, Hao J, Xu B, Wang Y, Li Y. Impact of previous Caesarean section on reproductive outcomes after assisted reproductive technology: systematic review and meta-analyses. Reproductive biomedicine online. 2021;43(2):197\u0026ndash;204. https://doi.org/10.1016/j.rbmo.2021.04.007.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBulletti FM, Sciorio R, Conforti A, De Luca R, Bulletti C, Palagiano A, Berrettini M, Scaravelli G, Pierson RA. Causes of embryo implantation failure: A systematic review and metaanalysis of procedures to increase embryo implantation potential. Front Endocrinol. 2025;15:1429193.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang YQ, Yin TL, Xu WM, Qi QR, Wang XC, Yang J. Reproductive outcomes in women with prior caesarean section undergoing in vitro fertilization: a retrospective case-control study. J Huazhong Univ Sci Technol Med Sci. 2017;37(6):922\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMorlando M, Conte A, Schiattarella A. Reproductive outcome after cesarean scar pregnancy. Best Pract Res Clin Obstet Gynecol. 2023;91. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003edoi.org/10.1016/j.bpobgyn.2023.102362\u003c/span\u003e\u003cspan address=\"10.1016/j.bpobgyn.2023.102362\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBusnelli A, Levi-Setti PE, Inversetti A, Bignardi T, Vitagliano A, Dell\u0026rsquo;Acqua C, Zambella E, Simone ND. Investigating the impact of isthmocele and its surgical repair on fertility: results from a systematic review and meta-analysis. Reprod Biomed Online. 2024. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003edoi.org/10.1016/j.rbmo.2024.104746\u003c/span\u003e\u003cspan address=\"10.1016/j.rbmo.2024.104746\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang Y, de Ziegler D, Hu X, Tai X, Han Y, Ma J, Zhang Y, Luo H. Previous caesarean delivery and the presence of caesarean scar defects could affect pregnancy outcomes after in vitro fertilization frozen-thawed embryo transfer: a retrospective cohort study. BMC Pregnancy Childbirth. 2022;22(1):769. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s12884-022-05085-0\u003c/span\u003e\u003cspan address=\"10.1186/s12884-022-05085-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChoksi A, Harnisch B, Honig S. What Every Provider Should Know About the 2020\u0026ndash;2021 Updated AUA/ASRM Guidelines on Male Factor Infertility. Curr Sex Health Rep. 2022;14(2):31\u0026ndash;8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s11930-022-00325-y\u003c/span\u003e\u003cspan address=\"10.1007/s11930-022-00325-y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZegers-Hochschild F, Adamson GD, Dyer S, Racowsky C, de Mouzon J, Sokol R, Rienzi L, Sunde A, Schmidt L, Cooke ID, Simpson JL, van der Poel S. The International Glossary on Infertility and Fertility Care, 2017. Hum Reprod. 2017;32(9):1786\u0026ndash;801. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/humrep/dex234\u003c/span\u003e\u003cspan address=\"10.1093/humrep/dex234\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSmith GCS, Wood AM, Pell JP, Dobbie R. First caesarean birth and subsequent fertility. Fertil Steril. 2006;85:90\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTollanes MC, Melve KK, Irgens LM, Skjaerven R. Reduced fertility after caesarean delivery: a maternal choice. Obstet Gynecol. 2007;110:1256\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHuang J, Lin J, Cai R, et al. Effect of a prior caesarean delivery on pregnancy outcomes of frozen-thawed embryo transfer: a retrospective cohort study in a freeze-all setting. Acta Obstet Gynecol Scand. 2020;99(10):1303\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen N, Xu H, Wang Z, Sun B, Hu H. Pregnancy, delivery, and neonatal outcomes of in vitro fertilization-embryo transfer in patient with previous caesarean scar. Med Sci Monit. 2016;16(22):3288\u0026ndash;95.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDiao J, Gao G, Zhang Y, Wang X, Zhang Y, Han Y, et al. Caesarean section defects may affect pregnancy outcomes after in vitro fertilization-embryo transfer: a retrospective study. BMC Pregnancy Childbirth. 2021;21(1):487.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCimadomo D, Fabozzi G, Vaiarelli A, et al. Impact of maternal age on oocyte and embryo competence. Front Endocrinol (Lausanne). 2018;29(9):327.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTsuji S, Nobuta Y, Hanada T, Takebayashi A, Inatomi A, Takahashi A, Amano T, Murakami T. Prevalence, definition, and etiology of cesarean scar defect and treatment of cesarean scar disorder: A narrative review. Reproductive Med biology. 2023;22(1):e12532. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/rmb2.12532\u003c/span\u003e\u003cspan address=\"10.1002/rmb2.12532\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDonnez O. Cesarean scar defects: management of an iatrogenic pathology whose prevalence has dramatically increased. Fertil Steril. 2020;113(4):704\u0026ndash;16. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.fertnstert.2020.01.037\u003c/span\u003e\u003cspan address=\"10.1016/j.fertnstert.2020.01.037\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"embryo transfer, Caesarean scar defect, clinical pregnancy, embryo implantation, IVF, /ICSI","lastPublishedDoi":"10.21203/rs.3.rs-7255223/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7255223/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction:\u003c/h2\u003e\u003cp\u003eThe mode of prior delivery may significantly affect the success of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) and subsequent pregnancy outcomes. This study evaluates the impact of vaginal delivery (VD), Caesarean section (CS) without scar defect, and CS with scar defect (CSD) on IVF/ICSI outcomes.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e\u003cp\u003eIn this study, 2284 women who underwent IVF/ICSI between 2020\u0026ndash;2023 in Abha City, Saudi Arabia, were stratified into three groups: prior VD (Group I, *n* = 1109), CS without scar defect (Group II, *n* = 742), and CS with CSD (Group III, *n* = 433). Pregnancy outcomes were compared using binary logistic regression, adjusting for confounders.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eIn this study, the differences between Groups I and II in live birth rates, implantation success, or clinical/ectopic pregnancy were found to be significant. However, Group III demonstrated significantly lower clinical pregnancy rates (27.9% vs. 63.3%, *p* \u0026lt; 0.05) and implantation success compared to Group I. Subgroup analysis revealed pronounced reductions in implantation, clinical pregnancy, and live birth rates among women\u0026thinsp;\u0026le;\u0026thinsp;35 years in Group III versus Group I (*p* \u0026lt; 0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eCSD\u0026mdash;but not CS alone\u0026mdash;adversely affects IVF/ICSI outcomes, particularly in younger women. These findings underscore the importance of optimizing surgical techniques to prevent CSD formation and preserve fertility. Future studies should investigate strategies to enhance uterine healing post-CS and improve ART success rates.\u003c/p\u003e","manuscriptTitle":"The Impact of Previous Caesarean Delivery on IVF/ICSI Outcomes: A Retrospective Cohort Study on experience from Saudi Arabia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-09 19:47:11","doi":"10.21203/rs.3.rs-7255223/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2025-09-30T08:43:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"143065186352962496241880983389005755977","date":"2025-09-15T15:09:30+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-03T06:59:20+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-08-05T09:26:15+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-01T12:22:40+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-01T12:21:02+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pregnancy and Childbirth","date":"2025-07-30T16:59:26+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"34ff4b4a-e8cf-471c-9d6a-6d63126ecbb0","owner":[],"postedDate":"September 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-09-09T19:47:11+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-09 19:47:11","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7255223","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7255223","identity":"rs-7255223","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}