The clinical efficacy evaluation of endometrial receptivity analysis (ERA) and Study on the influence factors of displaced window of implantation (WOI): A 6-year retrospective study on a large sample

The clinical efficacy evaluation of endometrial receptivity analysis (ERA) and Study on the influence factors of displaced window of implantation (WOI): A 6-year retrospective study on a large sample | 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 clinical efficacy evaluation of endometrial receptivity analysis (ERA) and Study on the influence factors of displaced window of implantation (WOI): A 6-year retrospective study on a large sample Shaoyuan Xu, Honglu Diao, Yao Xiong, Changjun Zhang, Ying Zhang, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4374140/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: The endometrium in a receptive status is critical for a successful embryo implantation, but the receptivity of endometrium to embryos is only a short period of time, and the window of implantation (WOI) of each woman has individual variation, which will lead to poor outcomes of assisted reproduction. This so-called window of implantation can be detected by molecular diagnostic method, endometrial receptivity analysis (ERA), which was gradually applied to clinical practice. This study aimed to evaluate the clinical efficacy of personalized embryo transfer (pET) guided by ERA in patients with and without RIF, statistically analyze the clinical factors correlated with displaced WOI. Methods: A total of 3605 patients with previous failed embryo transfer (ET) cycle in the Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine from January 2016 to October 2022 were retrospectively analyzed. 3605 patients were divided into non-RIF group and RIF group, among them 782 patients who received ERA test underwent personalized embryo transfer (pET). The decision whether to accept ERA test or not was based on the patient's voluntary choice. We divided the 782 patients into normal WOI group and displaced WOI group according to the result of ERA test. The pregnancy outcomes were compared between the different groups. The age, number of previous ET cycle and serum E2/P ratio were mainly analyzed to investigate its relationship with displaced WOI. Results: The clinical pregnancy rate and live birth rate in non-RIF with pET group were higher than that of non-RIF with non-personalized embryo transfer (npET) group (64.5% vs 58.3%, P=0.025; 57.1% vs 48.3%, P=0.003). The clinical pregnancy rate and the live birth rate in RIF with pET group were significantly higher than that of RIF with npET group (62.7% vs 49.3%, P<0.001; 52.5% vs 40.4%, P<0.001) after propensity score matching (PSM). The early abortion rate in the non-RIF with pET group was lower than that in the non-RIF with npET group (8.2% vs 13.0%, P=0.038). There was a significant difference in age and the number of previous failed ET cycle between the normal WOI group and displaced WOI group (age:32.26 vs 33.53 years, P<0.001; the number of previous failed ET cycle:1.68 vs 2.04, P< 0.001). Logistic regression analysis also showed that the age and number of previous failed ET cycles were positively correlated with displaced WOI. The displaced WOI rate increased gradually with the increase of age and number of previous failed ET cycle; the displaced WOI rate in the median group 4.46<E2/P≤10.39 pg/ng was significantly lower than that in the other two groups (54.8% vs 40.6% vs 58.5%, P<0.001). Conclusion: The clinical pregnancy rate and live birth rate of patients with previous failed ET cycle was improved after pET guided by ERA, especially in RIF patients; the early abortion rate of the non-RIF patient was reduced after pET guided by ERA. An appropriate E2/P ratio was beneficial for maintaining endometrial receptivity state, and the age and number of previous failed ET cycle was correlated with increased displaced WOI. Endometrial receptivity Windows of implantation Personalized embryo transfer Implantation failure E2/P ratio Clinical pregnancy Live birth Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction The relationship between Embryo quality and endometrial receptivity is similar to "seed" and "soil" in the process of assisted reproductive technology (ART). Successful embryo implantation requires capable embryo, receptive endometrium, and synchronous dialogue between maternal and embryonic tissue [ 1 ]. With the improvement of laboratory technology in in vitro fertilization-embryo transfer (IVF), great progress has been made in culturing and screening high-quality embryos at present [ 2 ], but some patients still face the thorny situation of implantation failure with high-quality embryo [ 3 ]. Another important factor to a successful embryo implantation is endometrial receptivity, which has attracted more and more attention. Endometrial receptivity refers to the period of endometrial maturation during which the trophectoderm of the blastocyst can attach to the endometrial epithelial cells and subsequently invade the endometrial stroma and vasculature [ 4 ]. As in humans, the endometrium undergoes a series of dynamic and complex changes during the menstrual cycle, and blastocysts are allowed to implant in a brief period, this period is called window of implantation (WOI), which is usually around days 19–24 of the menstrual cycle [ 5 ]. However, the WOI of each woman has an individual variation, and some women will have displace-WOI, this may lead to embryo-endometrium asynchrony, which usually leads to implantation failure or even recurrent implantation failure (RIF) [ 6 , 7 ]. If we can accurately detect the normal window of implantation and make a personalized embryo transfer, it will provide new possibilities to improve pregnancy rate of assisted reproduction. In the past, the time of endometrial window of implantation was mainly judged by transvaginal ultrasound, serum estrogen and progesterone levels, endometrial biopsy and other methods, but these methods have certain limitations and poor repeatability [ 8 , 9 ]. With the continuous development of modern molecular gene diagnosis technologies such as gene transcriptome analysis based on high-throughput sequencing technology, array endometrial receptivity analysis technology developed by combining computer programs [ 10 ]. Furthermore, the expense and invasive nature of ERA continue to be obstacle for the infertile patients, not every patient is willing to undergo ERA test. Therefore, it is also important to screen patients who are more likely to have a displaced WOI and need to undergo ERA test. In this study, we evaluated the clinical efficacy of personalized embryo transfer (pET) guided by ERA in patients with and without RIF, and analyzed the clinical factors correlated with displaced window of implantation. Materials and methods Study setting and patients 3605 patients with previous failed embryo transfer (ET) cycle in the Department of Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine from January 2016 to October 2022 were retrospectively analyzed. The patient was only be included once in the study if they underwent more than one ET cycles, and patients whose embryos were tested for aneuploidy using PGT-A screening were not included in this study. Among the 3605 patients, 782 patients received ERA and underwent personalized embryo transfer (pET) in accordance with the ERA test results in next hormone replacement therapy (HRT) cycle. In the same period, there were 2823 patients who did not received ERA and underwent non-personalized embryo transfer (npET) at a standardized FET time of P + 5d in HRT cycle. According to the definition of RIF, we divided these 3605 patients into non-RIF group (including 301 cases who received ERA and 1744 cases who did not received ERA) and RIF group (including 481 cases who received ERA and 1079 cases who did not received ERA). We furtherly divided the 782 patients who received ERA into two groups according to the result of ERA test: normal WOI group and displaced WOI group. This study was approved by the Ethics Committee of Renmin Hospital, Hubei University of Medicine (reference number: syrmyy2023-052) and conducted in conformity with the Helsinki Declaration. The exclusion criteria were as follows: (i) Patients with uterine and endometrial factors that may affect endometrial receptivity, such as chronic endometritis, severe intrauterine adhesions, endometrial tuberculosis, endometrial hyperplasia, uterine malformations, severe hydrosalpinx, severe endometriosis (stage III-IV) etc.; (ii) Other patients with severe underlying diseases which are not suitable for pregnancy (including tumor, hypertension, diabetes, etc.). RIF was defined as failure to achieve a clinical pregnancy after receiving at least 4 morphologically high-quality cleavage embryos or 2 high quality blastocysts in a minimum of 2 fresh or frozen transfer cycles [ 11 , 12 ]. The criteria for embryos of high quality were as follows: (i) Blastocysts: ≥3BB [ 13 ]; (ii) Cleavage-stage embryo: number of cells ≥ 8, fragmentation < 20% and uniform size of blastomeres [ 14 ]. Endometrial sampling and preparing HRT protocol was used in the endometrial preparing. Estrogen (oral or external use, and both if necessary) should be pretreated for 16 days from the third day of menstruation, the ultrasound was used to assess the thickness of the endometrium, if the thickness is greater than six millimeters, then progesterone (P)60mg is injected intramuscularly. The first day of progesterone supplementation is regarded as P + 0d, lasting for 5days, and endometrial biopsy should be performed at P + 5d. Endometrial receptivity testing Endometrial receptivity test in our center is based on endometrial receptivity gene chip which is consisted of a customized array containing 238 genes expressed at different stages of the endometrial cycle [ 15 ]. Endometrial receptivity status can be predicted through computer analysis. The detailed process of endometrial receptivity test can be seen in Fig. 1 The receptivity or non-receptivity was reported by ERA test, and the results of non-receptivity were divided into proliferative, pre-receptivity and post-receptivity. For patients with non-receptivity state, they were biopsied again at the recommended time of the ERA test in subsequent cycles until the receptivity state is found. For patients with receptivity state detected by ERA, pET usually carries out in the next HRT-FET cycle at normal WOI time. The primary outcome measures Clinical pregnancy was defined as ultrasonography showing a pregnancy sac after receiving embryo transfer four weeks later. Clinical pregnancy rate = number of pregnancy cycles/number of transplantation cycles ×100%. Live birth was defined as giving birth to at least one live infant, and the gestational age was longer than 28 weeks. live birth rate = number of births of live babies/number of total transplantation cycles ×100%. Statistical analysis methods Our data collection and analysis method is shown in Fig. 2 . SPSS26.0 software was used for statistical analysis. The measurement data conform to the normal distribution expressed by the mean standard deviation (Mean ± SD), and the comparison between groups was made by one-way ANOVA. The counting data is expressed by the rate (%), and the comparison between groups adopts χ2 test; Because there had significant differences in characteristics between the RIF patient with pET and npET group, we used propensity score matching (PSM) to adjust for potential differences in characteristics, and nearest neighbor matching method was use for PSM. The variables included in PSM are those with differences between the two groups: Age, Infertility type, Basal serum FSH, Basal LH. ERA patients with RIF were matched to non-ERA patients ERA patients with RIF in a 1:2 matching ratio, the caliper value was set to 0.1. The majority of ERA patients with RIF were successfully matched to 2 non-ERA patients with RIF. Logistic regression analysis was used to exclude the influence of confounding factor and analyze the correlation between related factors and displace WOI. P < 0.05 is the difference with statistical significance. Results Comparison baseline characteristics and pregnancy outcomes in non-RIF patients with pET and npET The comparison of basic characteristics showed no significant difference between the non-RIF with pET and non-RIF with npET groups, indicating comparability between the two groups. The clinical pregnancy rate and live birth rate in non-RIF with pET group were higher than that of non-RIF with npET group (64.5% vs 58.3%, P=0.025; 57.1% vs 48.3%, P=0.003). Moreover, the early abortion rate in the non-RIF with pET group was lower than that in the non-RIF with npET group (8.2% vs 13.0%, P=0.038). There was no difference in the ectopic pregnancy rate between the two groups. See Table 1, Fig. 3 for details. Comparison basic characteristics and pregnancy outcomes in RIF patients with pET and npET There were significant differences in patient characteristics of female age, infertility type, BMI, basal serum PRL between the RIF with pET and RIF with npET groups. We used propensity score matching (PSM) to adjust for potential differences in characteristics, the matching ratio was set to 1:2, and 434 patients in RIF with pET group were matched to755 patients in RIF with non-pET group. The clinical pregnancy rate and the live birth rate in RIF with pET group were significantly higher than that of RIF with npET group after PSM (62.7% vs 49.3%, P<0.001; 52.5% vs 40.4%, P<0.001). There is no difference in the early abortion rate and ectopic pregnancy rate between the two groups. See Table 2, Fig. 3 for details. Endometrial receptivity testing results Among the 782 patients who underwent ERA test on P+5d, 381 (48.7%) patients were found to be receptive, and diagnosed with normal WOI; 401 patients (51.3%) were found to be non-receptive, and diagnosed with displaced WOI. All the 401 patients with a displaced WOI were biopsied again at the recommended time of the ERA test in subsequent cycles until the receptivity state is found. Finally, among the 401patients with a displaced WOI, 245 patients went through two ERA test and find the receptive state; 156 patients went through three ERA test and find the receptive state. Comparison of Normal WOI and Displaced WOI group in patients who underwent ERA test There was a significant difference in age and the number of previous failed ET cycle between the normal WOI group and displaced WOI group (age:32.26 vs 33.53 years, P<0.001; the number of previous failed ET cycle:1.68 vs 2.04, P< 0.001). There was no significant difference in other factors including serum E2 and P levels on P+5d between the normal WOI group and displaced WOI group. See Table 3 for details. The logistic regression analysis was performed to evaluate the correlation between related factors and displaced WOI with a enter regression method The results showed that age and number of previous failed ET cycles were positively correlated with displaced WOI, while other variables, including serum E2 and P, were not in linear correlation with endometrial receptivity. See Table 4 for details. Correlation analysis between E2/P ratio, age, number of previous failed ET cycle and displaced WOI We divided 782 patients who received ERA test into three groups according to their age: age≤30 years group, 30 years35 years group, the results showed that the displaced WOI rate increased gradually with the increase of age group (42.0% vs 51.6% vs 61.0%, P<0.001) (Table 5, Fig. 4A) We divided these 782 patients who received ERA test into three groups according to the number of previous failed ET cycles: number of previous failed ET cycle=1 group, =2 group, and≥3 group, the results showed that the displaced WOI rate increased gradually with the increase of the number of previous failed ET cycle (40.9% vs 54.6% vs 65.3%, P<0.001) (Table 5, Fig. 4B). We divided 782 patients with ERA test into tertiles for analysis according to the E2/P ratios: E2/P≤4.46 pg/ng group, 4.4610.39 pg/ng group. The results showed that the displaced WOI rate of the median group 4.46<E2/P≤10.39 pg/ng was significantly lower than that of the other two groups (54.8% vs 40.6% vs 58.5%, P<0.001) (Table 5, Fig. 4C). Discussion Traditionally, the WOI period is considered quite wide, but the optimal window has been proved to be much narrower, which may last for only 12 ~ 48h [ 16 ]. The embryo transplantation outside the window will lead to poorer outcomes of assisted reproductive treatment [ 6 , 7 ]. Therefore, it is very important to detect the normal WOI objectively for personalized embryo transfer (pET). It is reported that nearly 1/3 to 2/3 of implantation failures are caused by the endometrial non-receptivity status [ 17 , 18 ]. It has been reported that the pregnancy outcomes of patients who received ERA test significantly increased compared with control group, especially in patients with RIF [ 19 , 20 ]. However, there are also recent studies hold the opposite opinions that ERA can not improve the pregnancy outcome in RIF patients [ 21 , 22 ]. Other investigators considered that the value was rather limited when applied ERA in the first embryo transfer cycles or on the patient with good prognosis, ERA were not recommended as a routine test for unselected patient populations [ 23 , 24 ]. Because some factors can affect endometrial gene expression, including chronic endometritis, severe intrauterine adhesions, endometrial tuberculosis, endometrial hyperplasia, etc. [ 25 – 27 ], so we excluded some factors that may affect endometrial receptivity to eliminate these biases. In this study, we divide the population into two categories: non-RIF and RIF, and we found that non-RIF with pET group had higher clinical pregnancy rates (64.5% vs 58.3%, P = 0.025) and live birth rate (57.1% vs 48.3%, P = 0.003) than non-RIF with npET group. The pregnancy rate in RIF with pET group (62.7% vs 49.3%, P < 0.001) and the live birth rate (52.5% vs 40.4%, P < 0.001) are significantly higher than RIF with non-pET group after PSM matching, and the gap of pregnancy outcomes between the RIF with pET group and npET group is larger than that of non- RIF with pET and npET group. This study further confirmed the clinical value of ERA in infertile patients with previous failed ET cycle, especially in RIF patients. Not only that, we also found that for patients with non-RIF, pET guided by ERA has a certain effect on reducing the early spontaneous abortion rate. This is a new discovery, indicating that the displacement of the implantation window may be related to early abortion. However, for RIF patients, pET did not have such an effect, we believe the possible reasons are that patients with RIF have numerous other factors that can lead to miscarriage, including factors such as aneuploidy [ 28 – 31 ]. But we need to pay attention to another point of endometrial scraping, which is an intentional damage to the endometrium that is carried out with the aim of improving outcomes from fertility treatment or the chance of natural conception [ 32 , 33 ]. So, the improvement in pregnancy outcomes may be related to endometrial scraping caused by endometrial biopsy during ERA test, but we cannot rule out the influence of this confounding factor, which is also the limitation of this article. Embryo implantation is a process in which the endometrium in receptive state interacted with functional embryos, then the trophoblast established close links with the decidualized endometrium, which is controlled by estrogen, progesterone and a large number of transcription factors [ 1 ]. In this complex physiological process, numerous of molecular mediators participate in the initial maternal-fetal interaction under the coordination of ovarian steroid hormones [ 34 ]. Although it is known that ovaries produce many steroids throughout the menstrual cycle, only E2 and P have been proven to be essential for inducing endometrial receptivity [ 5 , 35 ]. Studies have shown that the disorder of the sex hormone will affect the endometrial receptivity [ 36 , 37 ], and low serum progesterone on day of transfer adversely impacts ongoing pregnancy rates in hormonally prepared single blastocyst frozen embryo transfer cycles [ 38 ]. Progesterone in advance can reduce pregnancy rate [ 39 ]. Research has confirmed that exposure of human endometrial epithelial cells to high levels of estrogen can lead to abnormal expression of many key implantation molecules [ 40 ]. Estradiol reduction adversely affect the embryo quality and clinical outcomes of IVF-ET [ 41 ]. However, these studies did not combine estrogen and progesterone with gene expression profile. There are currently no reports linking endometrial receptivity testing with hormone analysis for research. In this study, we measured the serum estrogen and progesterone levels on P + 5d, and compared the estrogen and progesterone levels between the normal and displaced WOI groups, but there is no difference between the two groups, and the logistic regression analysis also showed that the estrogen and progesterone levels were not linearly correlated with the displaced WOI. Therefore, we divided the E2/P values into tertiles for analysis, we found that the displaced WOI rate of the median group 4.46 < E2/P ≤ 10.39 pg/ng was significantly lower than that of the other two groups, which indicated that an appropriate E2/P ratio value was important for maintaining the endometrial receptivity state. Age is an important influencing factor on pregnancy rate of assisted reproduction. There have some studies reported the relationship between advanced maternal age and decline of endometrial receptivity [ 42 – 44 ], but all these reports studied the endometrial receptivity from the standpoint of pregnancy outcomes. So far, there has no studies combined age with the gene expression test of endometrial receptivity. Our study showed that there has a significant difference in age between the normal WOI and displaced WOI patients, and the results of logistic regression analysis also showed that age was positively correlated with displaced WOI. We divided all patients who received ERA test into three groups according to their age, we found that the displaced WOI rate increased gradually with the increase of age group, which indicated that as age increases, the occurrence probability of displaced WOI also gradually increases. We also found that there was a significant difference in the number of previous failed ET cycle between the normal WOI and displaced WOI patients, and the results of logistic regression analysis also showed that the number of previous failed ET cycle was positively correlated with the displaced WOI. According to the number of previous failed ET cycle, we divided the patients into three groups for detailed analysis, and we found that the displaced WOI rate increased gradually with the increase of the number of previous failed ET cycle. Our result showed that the higher the number of previous failed cycle, the greater the likelihood of displaced WOI in patients. Psychological pressure and loss of hope for success are factors that must be taken seriously in the progress of assisted reproduction [ 45 ]. According to reports, a surprising number of couples stop continuing treatment after at least one failed IVF cycle [ 46 ]. The cause of implantation failure is due partly to individual differences of WOI. According to our study, we suggest that positive actions including endometrial receptivity assessments are recommended to improve the outcomes of assisted reproduction for elderly patients and patients who have experienced one or more failed cycles. As our study suggests that the endometrial receptivity is influenced by some maternal factors, including age-time changes, hormonal changes, and there maybe has some other unknown factors. Due to the invasive examination of endometrial biopsy, embryo transfer cannot be performed during the biopsy cycle. So, the endometrial receptivity status during the biopsy cycle may differ from the actual embryo transfer cycle, which may also lead to different outcomes. We believe this may also be a reason for controversy regarding the application of ERA. Therefore, it is necessary to search for new non-invasive methods for ERA. Conclusions The clinical pregnancy rate and live birth rate of patients with previous failed ET cycle was improved after pET guided by ERA, especially in RIF patients; the early abortion rate of the non-RIF patient was reduced after pET guided by ERA. Moreover, we firstly found that an appropriate E2/P ratio is beneficial for maintaining endometrial receptivity state, and the probability of displacement WOI will increase with age and number of previous failed ET cycle. Declarations Authors’ contributions S.Y.X contributed to statistical analysis and interpretation of data and drafting of the manuscript. Y.Z and Y.Z.Z conceived and designed this study, performed statistical analysis and participated in the discussion. H.L.D and Y.X were involved in acquisition, analysis and interpretation of data. S.Y.X, YZ, C.J.Z and Y.Z.Z participated in the discussion and critically revised the manuscript. Acknowledgements None Funding This study was supported by a research grant (No.81771543) from the National Natural Science Foundation of China. Availability of data and materials Data will be available on request. Ethics approval and consent to participate This study was approved by the Ethics Committee of Renmin Hospital, Hubei University of Medicine (reference number: syrmyy2023-052) and conducted in conformity with the Helsinki Declaration. Written informed consent was waived due to the retrospective nature, and patients’ data were used anonymously. Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests. References Awonuga AO, Camp OG, Abu-Soud HM, et al. Determinants of Embryo Implantation: Roles of the Endometrium and Embryo in Implantation Success. Reprod Sci. 2023 Aug;30(8):2339-2348. Massarotti C, Makieva S, Stigliani S. Editorial: Challenges in fertilization and implantation success. 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Vomstein K, Reider S, Böttcher B, et al. Uterine microbiota plasticity during the menstrual cycle: Differences between healthy controls and patients with recurrent miscarriage or implantation failure. J Reprod Immunol. 2022 Jun;151:103634. Stevens Brentjens L, Habets D, Den Hartog J, et al. Endometrial factors in the implantation failure spectrum: protocol of a MUltidisciplinary observational cohort study in women with Repeated Implantation failure and recurrent Miscarriage (MURIM Study). BMJ Open. 2022 Jun 8;12(6):e056714. ESHRE Working Group on Recurrent Implantation Failure; Cimadomo D, de Los Santos MJ, Griesinger G, Lainas G, Le Clef N, McLernon DJ, Montjean D, Toth B, Vermeulen N, Macklon N. ESHRE good practice recommendations on recurrent implantation failure. Hum Reprod Open. 2023 Jun 15;2023(3):hoad023. Palomba S, Vitagliano A. Is the era of the endometrial scratching finished? Fertil Steril. 2022 Sep;118(3):603. Wong TY, Lensen S, Wilkinson J, et al. Effect of endometrial scratching on unassisted conception for unexplained infertility: a randomized controlled trial. Fertil Steril. 2022 Mar;117(3):612-619. Stevens Brentjens LBPM, Obukhova D, den Hartog JE, et al. An integrative analysis of endometrial steroid metabolism and transcriptome in relation to endometrial receptivity in in vitro fertilization patients. F S Sci. 2023 Aug;4(3):219-228. Perry GA, Ketchum JN, Quail LK. Importance of preovulatory estradiol on uterine receptivity and luteal function. Anim Reprod. 2023 Sep 4;20(2):e20230061. Al-Lamee H, Ellison A, Drury J, et al. Altered endometrial oestrogen-responsiveness and recurrent reproductive failure. Reprod Fertil. 2022 Feb 21;3(1):30-38. Parisi F, Fenizia C, Introini A, et al. The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester. Hum Reprod Update. 2023 Jun 23:dmad016. Shekhar B, Mittal S, Majumdar G, et al. Low serum progesterone on day of transfer adversely impacts ongoing pregnancy rates in hormonally prepared single blastocyst frozen embryo transfer cycles. Eur J Obstet Gynecol Reprod Biol. 2023 Oct;289:55-59. Gurunath S. Premature Progesterone Elevation in in vitro Fertilisation Cycles - Current Perspectives. J Hum Reprod Sci. 2022 Oct-Dec;15(4):325-336. Ullah K, Rahman TU, Pan HT, et al. Serum estradiol levels in controlled ovarian stimulation directly affect the endometrium. J Mol Endocrinol. 2017 Aug;59(2):105-119. Cheng J, Yang S, Ma H, Liang Y, Zhao J. Estradiol (E2) Reduction Adversely Affect the Embryo Quality and Clinical Outcomes of In Vitro Fertilization and Embryo transfer (IVF-ET). J Healthc Eng. 2022 Apr 7;2022:2473876. Pathare ADS, Loid M, Saare M, et al. Endometrial receptivity in women of advanced age: an underrated factor in infertility. Hum Reprod Update. 2023 Jul 19:dmad019. Shao Y, Feng H, Li L, Zong Y, Liang J. Predictive Value of Endometrial Receptivity for Pregnancy Outcomes of In-vitro Fertilization Embryo Transfer for Patients of Different Ages. Altern Ther Health Med. 2023 May;29(4):210-217. Zhao J, Huang B, Li N, et al. Relationship between advanced maternal age and decline of endometrial receptivity: a systematic review and meta-analysis. Aging (Albany NY). 2023 Feb 27;15(7):2460-2472. Sharma A, Shrivastava D. Psychological Problems Related to Infertility. Cureus. 2022 Oct 15;14(10):e30320. Kulkarni G, Mohanty NC, Mohanty IR, et al. Survey of reasons for discontinuation from in vitro fertilization treatment among couples attending infertility clinic. J Hum Reprod Sci. 2014 Oct-Dec;7(4):249-54. Tables Tables 1 to 5 are available in the Supplementary Files section. Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4374140","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":301811816,"identity":"a29ac28c-855b-4db8-872c-b9ee4fc562ee","order_by":0,"name":"Shaoyuan Xu","email":"","orcid":"","institution":"Zhongnan Hospital of Wuhan University","correspondingAuthor":false,"prefix":"","firstName":"Shaoyuan","middleName":"","lastName":"Xu","suffix":""},{"id":301811817,"identity":"b2053ba2-bb0d-4c3d-a85a-95f1d6985880","order_by":1,"name":"Honglu Diao","email":"","orcid":"","institution":"Hubei University of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Honglu","middleName":"","lastName":"Diao","suffix":""},{"id":301811818,"identity":"cfdd24de-9067-491b-b9be-934674ca48cd","order_by":2,"name":"Yao Xiong","email":"","orcid":"","institution":"Zhongnan Hospital of Wuhan University","correspondingAuthor":false,"prefix":"","firstName":"Yao","middleName":"","lastName":"Xiong","suffix":""},{"id":301811819,"identity":"4b2c5f8b-7ba4-46ef-a4c8-b3646721543d","order_by":3,"name":"Changjun Zhang","email":"","orcid":"","institution":"Hubei University of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Changjun","middleName":"","lastName":"Zhang","suffix":""},{"id":301811820,"identity":"a2298e0a-0d00-4ebb-9909-30207f68f318","order_by":4,"name":"Ying Zhang","email":"","orcid":"","institution":"Hubei University of Medicine","correspondingAuthor":false,"prefix":"","firstName":"Ying","middleName":"","lastName":"Zhang","suffix":""},{"id":301811821,"identity":"8dc87ed9-58df-44ad-86fc-1ca28e002a68","order_by":5,"name":"Yuanzhen Zhang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABAUlEQVRIiWNgGAWjYDACCTiLB4grGBJQBQlrOUOyFsY2IrTIz25+9vBr22F5c/6zBx8XzjucZ3CA+eBtHga7PFxaGOccMzeWbTtsuLPhXLLxzG2Hiw0OsCVb8zAkF+PSwiyRYCYt2XaYccPBHjNp3m23Ezcc4DGT5mE4kNiAQwubRPo3kBb7DYd5zH/zzgFp4f+GVwuPRI6Z5Me2w4kbjvGYMfM2gG1hw6tFQiKnTJrhXHryhjM8xtI8x/4nzjzMZmw5xyAZpxb5GenbJH+UWdtuOH/G8DNPTVpi3/HmhzfeVNjh1AIOAl42FC6IMMCjHggYf/zBr2AUjIJRMApGOAAAnZxYEboafkAAAAAASUVORK5CYII=","orcid":"","institution":"Zhongnan Hospital of Wuhan University","correspondingAuthor":true,"prefix":"","firstName":"Yuanzhen","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2024-05-06 05:09:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4374140/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4374140/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":56682467,"identity":"979becf7-09ab-4aed-87fc-858dd8cb3d12","added_by":"auto","created_at":"2024-05-17 18:25:34","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":68637,"visible":true,"origin":"","legend":"\u003cp\u003eThe detailed process of endometrial receptivity test.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4374140/v1/29cee1b59f43e0745861b598.jpg"},{"id":56682466,"identity":"56395edc-27fc-4886-b6f6-d42635e6e879","added_by":"auto","created_at":"2024-05-17 18:25:34","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":193107,"visible":true,"origin":"","legend":"\u003cp\u003eThe detailed process of data collection and analysis method.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4374140/v1/c2743e0c5ec6c426dfbc376c.jpg"},{"id":56682468,"identity":"7398adf2-7393-4f97-bdaa-818683258004","added_by":"auto","created_at":"2024-05-17 18:25:34","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":60697,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of pregnancy outcomes of pET and npET in non-RIF and RIF patients. (A) Clinical pregnancy; (B) Live birth rate; (C) Early abortion rate.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4374140/v1/24e14035d2d58b8579e56ba5.jpg"},{"id":56682465,"identity":"09c6adc1-1590-4094-9359-c57d630a0248","added_by":"auto","created_at":"2024-05-17 18:25:34","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":65352,"visible":true,"origin":"","legend":"\u003cp\u003eGroup comparison to analysis correlation between related factors and displaced. (A) age group; (B) No. of previous failed ET cycle group; (C) E2/P ratios group\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4374140/v1/c29a025cb17952aee6dc1b74.jpg"},{"id":58382688,"identity":"8f20aee4-27f7-4a63-82f8-49353dbf49ab","added_by":"auto","created_at":"2024-06-14 17:45:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":917537,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4374140/v1/ad4400ce-ac46-480e-a23b-2de6c17be23f.pdf"},{"id":56682464,"identity":"e1ac9bcb-d956-4a5e-9433-ba17fef160c9","added_by":"auto","created_at":"2024-05-17 18:25:33","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":33307,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-4374140/v1/7116ab137eb5f9a6f6212f5b.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The clinical efficacy evaluation of endometrial receptivity analysis (ERA) and Study on the influence factors of displaced window of implantation (WOI): A 6-year retrospective study on a large sample","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe relationship between Embryo quality and endometrial receptivity is similar to \"seed\" and \"soil\" in the process of assisted reproductive technology (ART). Successful embryo implantation requires capable embryo, receptive endometrium, and synchronous dialogue between maternal and embryonic tissue [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. With the improvement of laboratory technology in in vitro fertilization-embryo transfer (IVF), great progress has been made in culturing and screening high-quality embryos at present [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], but some patients still face the thorny situation of implantation failure with high-quality embryo [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Another important factor to a successful embryo implantation is endometrial receptivity, which has attracted more and more attention. Endometrial receptivity refers to the period of endometrial maturation during which the trophectoderm of the blastocyst can attach to the endometrial epithelial cells and subsequently invade the endometrial stroma and vasculature [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. As in humans, the endometrium undergoes a series of dynamic and complex changes during the menstrual cycle, and blastocysts are allowed to implant in a brief period, this period is called window of implantation (WOI), which is usually around days 19\u0026ndash;24 of the menstrual cycle [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, the WOI of each woman has an individual variation, and some women will have displace-WOI, this may lead to embryo-endometrium asynchrony, which usually leads to implantation failure or even recurrent implantation failure (RIF) [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. If we can accurately detect the normal window of implantation and make a personalized embryo transfer, it will provide new possibilities to improve pregnancy rate of assisted reproduction.\u003c/p\u003e \u003cp\u003eIn the past, the time of endometrial window of implantation was mainly judged by transvaginal ultrasound, serum estrogen and progesterone levels, endometrial biopsy and other methods, but these methods have certain limitations and poor repeatability [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. With the continuous development of modern molecular gene diagnosis technologies such as gene transcriptome analysis based on high-throughput sequencing technology, array endometrial receptivity analysis technology developed by combining computer programs [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFurthermore, the expense and invasive nature of ERA continue to be obstacle for the infertile patients, not every patient is willing to undergo ERA test. Therefore, it is also important to screen patients who are more likely to have a displaced WOI and need to undergo ERA test. In this study, we evaluated the clinical efficacy of personalized embryo transfer (pET) guided by ERA in patients with and without RIF, and analyzed the clinical factors correlated with displaced window of implantation.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy setting and patients\u003c/h2\u003e \u003cp\u003e3605 patients with previous failed embryo transfer (ET) cycle in the Department of Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine from January 2016 to October 2022 were retrospectively analyzed. The patient was only be included once in the study if they underwent more than one ET cycles, and patients whose embryos were tested for aneuploidy using PGT-A screening were not included in this study. Among the 3605 patients, 782 patients received ERA and underwent personalized embryo transfer (pET) in accordance with the ERA test results in next hormone replacement therapy (HRT) cycle. In the same period, there were 2823 patients who did not received ERA and underwent non-personalized embryo transfer (npET) at a standardized FET time of P\u0026thinsp;+\u0026thinsp;5d in HRT cycle. According to the definition of RIF, we divided these 3605 patients into non-RIF group (including 301 cases who received ERA and 1744 cases who did not received ERA) and RIF group (including 481 cases who received ERA and 1079 cases who did not received ERA). We furtherly divided the 782 patients who received ERA into two groups according to the result of ERA test: normal WOI group and displaced WOI group. This study was approved by the Ethics Committee of Renmin Hospital, Hubei University of Medicine (reference number: syrmyy2023-052) and conducted in conformity with the Helsinki Declaration.\u003c/p\u003e \u003cp\u003eThe exclusion criteria were as follows: (i) Patients with uterine and endometrial factors that may affect endometrial receptivity, such as chronic endometritis, severe intrauterine adhesions, endometrial tuberculosis, endometrial hyperplasia, uterine malformations, severe hydrosalpinx, severe endometriosis (stage III-IV) etc.; (ii) Other patients with severe underlying diseases which are not suitable for pregnancy (including tumor, hypertension, diabetes, etc.).\u003c/p\u003e \u003cp\u003eRIF was defined as failure to achieve a clinical pregnancy after receiving at least 4 morphologically high-quality cleavage embryos or 2 high quality blastocysts in a minimum of 2 fresh or frozen transfer cycles [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The criteria for embryos of high quality were as follows: (i) Blastocysts: \u0026ge;3BB [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]; (ii) Cleavage-stage embryo: number of cells\u0026thinsp;\u0026ge;\u0026thinsp;8, fragmentation\u0026thinsp;\u0026lt;\u0026thinsp;20% and uniform size of blastomeres [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eEndometrial sampling and preparing\u003c/h2\u003e \u003cp\u003eHRT protocol was used in the endometrial preparing. Estrogen (oral or external use, and both if necessary) should be pretreated for 16 days from the third day of menstruation, the ultrasound was used to assess the thickness of the endometrium, if the thickness is greater than six millimeters, then progesterone (P)60mg is injected intramuscularly. The first day of progesterone supplementation is regarded as P\u0026thinsp;+\u0026thinsp;0d, lasting for 5days, and endometrial biopsy should be performed at P\u0026thinsp;+\u0026thinsp;5d.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eEndometrial receptivity testing\u003c/h2\u003e \u003cp\u003eEndometrial receptivity test in our center is based on endometrial receptivity gene chip which is consisted of a customized array containing 238 genes expressed at different stages of the endometrial cycle [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Endometrial receptivity status can be predicted through computer analysis. The detailed process of endometrial receptivity test can be seen in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe receptivity or non-receptivity was reported by ERA test, and the results of non-receptivity were divided into proliferative, pre-receptivity and post-receptivity. For patients with non-receptivity state, they were biopsied again at the recommended time of the ERA test in subsequent cycles until the receptivity state is found. For patients with receptivity state detected by ERA, pET usually carries out in the next HRT-FET cycle at normal WOI time.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eThe primary outcome measures\u003c/h2\u003e \u003cp\u003eClinical pregnancy was defined as ultrasonography showing a pregnancy sac after receiving embryo transfer four weeks later. Clinical pregnancy rate\u0026thinsp;=\u0026thinsp;number of pregnancy cycles/number of transplantation cycles \u0026times;100%. Live birth was defined as giving birth to at least one live infant, and the gestational age was longer than 28 weeks. live birth rate\u0026thinsp;=\u0026thinsp;number of births of live babies/number of total transplantation cycles \u0026times;100%.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis methods\u003c/h2\u003e \u003cp\u003eOur data collection and analysis method is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. SPSS26.0 software was used for statistical analysis. The measurement data conform to the normal distribution expressed by the mean standard deviation (Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD), and the comparison between groups was made by one-way ANOVA. The counting data is expressed by the rate (%), and the comparison between groups adopts χ2 test; Because there had significant differences in characteristics between the RIF patient with pET and npET group, we used propensity score matching (PSM) to adjust for potential differences in characteristics, and nearest neighbor matching method was use for PSM. The variables included in PSM are those with differences between the two groups: Age, Infertility type, Basal serum FSH, Basal LH. ERA patients with RIF were matched to non-ERA patients ERA patients with RIF in a 1:2 matching ratio, the caliper value was set to 0.1. The majority of ERA patients with RIF were successfully matched to 2 non-ERA patients with RIF. Logistic regression analysis was used to exclude the influence of confounding factor and analyze the correlation between related factors and displace WOI. P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 is the difference with statistical significance.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eComparison baseline characteristics and pregnancy outcomes in non-RIF patients with pET and npET\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe comparison of basic characteristics showed no significant difference between the non-RIF with pET and non-RIF with npET groups, indicating comparability between the two groups. The clinical pregnancy rate and live birth rate in non-RIF with pET group were higher than that of non-RIF with npET group (64.5% vs 58.3%, P=0.025; 57.1% vs 48.3%, P=0.003). Moreover, the early abortion rate in the non-RIF with pET group was lower than that in the non-RIF with npET group (8.2% vs 13.0%, P=0.038). There was no difference in the ectopic pregnancy rate between the two groups. See Table 1, Fig. 3 for details.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison basic characteristics and pregnancy outcomes in RIF patients with pET and npET\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were significant differences in patient characteristics of female age, infertility type, BMI, basal serum PRL between the RIF with pET and RIF with npET groups. We used propensity score matching (PSM) to adjust for potential differences in characteristics, the matching ratio was set to 1:2, and 434 patients in RIF with pET group were matched to755 patients in RIF with non-pET group. The clinical pregnancy rate and the live birth rate in RIF with pET group were significantly higher than that of RIF with npET group after PSM (62.7% vs 49.3%, P\u0026lt;0.001; 52.5% vs 40.4%, P\u0026lt;0.001). There is no difference in the early abortion rate and ectopic pregnancy rate between the two groups. See Table 2, Fig. 3 for details.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEndometrial receptivity testing results\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmong the 782 patients who underwent ERA test on P+5d, 381 (48.7%) patients were found to be receptive, and diagnosed with normal WOI; 401 patients (51.3%) were found to be non-receptive, and diagnosed with displaced WOI. All the 401 patients with a displaced WOI were biopsied again at the recommended time of the ERA test in subsequent cycles until the receptivity state is found. Finally, among the 401patients with a displaced WOI, 245 patients\u0026nbsp;went through two ERA test and find the receptive state; 156 patients\u0026nbsp;went through three ERA test and find the receptive state.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison of Normal WOI and Displaced WOI group in patients who underwent ERA test\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere was a significant difference in age and the number of previous failed ET cycle between the normal WOI group and displaced WOI group (age:32.26 vs 33.53 years, P\u0026lt;0.001; the number of previous failed ET cycle:1.68 vs 2.04, P\u0026lt; 0.001). There was no significant difference in other factors including serum E2 and P levels on P+5d between the normal WOI group and displaced WOI group. See Table 3 for details.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe logistic regression analysis was performed to evaluate the correlation between related factors and displaced WOI with a enter regression method\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe results showed that age and number of previous failed ET cycles were positively correlated with displaced WOI, while other variables, including serum E2 and P, were not in\u0026nbsp;linear correlation\u0026nbsp;with endometrial receptivity. See Table 4 for details.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrelation analysis between E2/P ratio, age, number of previous failed ET cycle and displaced WOI\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe divided 782 patients who received ERA test into three groups according to their age: age≤30 years group, 30 years\u0026lt;age≤35 years group, age\u0026gt;35 years group, the results showed that the displaced WOI rate increased gradually with the increase of age group (42.0% vs 51.6% vs 61.0%, P\u0026lt;0.001) (Table 5, Fig. 4A)\u003c/p\u003e\n\u003cp\u003eWe divided these 782 patients who received ERA test into three groups according to the number of previous failed ET cycles: number of previous failed ET cycle=1 group, =2 group, and≥3 group, the results showed that the displaced WOI rate increased gradually with the increase of the number of previous failed ET cycle (40.9% vs 54.6% vs 65.3%, P\u0026lt;0.001) (Table 5, Fig. 4B).\u003c/p\u003e\n\u003cp\u003eWe divided 782 patients with ERA test into tertiles for analysis according to the E2/P ratios: E2/P≤4.46 pg/ng group, 4.46\u0026lt;E2/P≤10.39 pg/ng group, E2/P\u0026gt;10.39 pg/ng group. The results showed that the displaced WOI rate of the median group 4.46\u0026lt;E2/P≤10.39 pg/ng was significantly lower than that of the other two groups (54.8% vs 40.6% vs 58.5%, P\u0026lt;0.001) (Table 5, Fig. 4C).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eTraditionally, the WOI period is considered quite wide, but the optimal window has been proved to be much narrower, which may last for only 12\u0026thinsp;~\u0026thinsp;48h [\u003csup\u003e16\u003c/sup\u003e]. The embryo transplantation outside the window will lead to poorer outcomes of assisted reproductive treatment [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Therefore, it is very important to detect the normal WOI objectively for personalized embryo transfer (pET). It is reported that nearly 1/3 to 2/3 of implantation failures are caused by the endometrial non-receptivity status [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. It has been reported that the pregnancy outcomes of patients who received ERA test significantly increased compared with control group, especially in patients with RIF [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However, there are also recent studies hold the opposite opinions that ERA can not improve the pregnancy outcome in RIF patients [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Other investigators considered that the value was rather limited when applied ERA in the first embryo transfer cycles or on the patient with good prognosis, ERA were not recommended as a routine test for unselected patient populations [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Because some factors can affect endometrial gene expression, including chronic endometritis, severe intrauterine adhesions, endometrial tuberculosis, endometrial hyperplasia, etc. [\u003cspan additionalcitationids=\"CR26\" citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], so we excluded some factors that may affect endometrial receptivity to eliminate these biases. In this study, we divide the population into two categories: non-RIF and RIF, and we found that non-RIF with pET group had higher clinical pregnancy rates (64.5% vs 58.3%, P\u0026thinsp;=\u0026thinsp;0.025) and live birth rate (57.1% vs 48.3%, P\u0026thinsp;=\u0026thinsp;0.003) than non-RIF with npET group. The pregnancy rate in RIF with pET group (62.7% vs 49.3%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and the live birth rate (52.5% vs 40.4%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) are significantly higher than RIF with non-pET group after PSM matching, and the gap of pregnancy outcomes between the RIF with pET group and npET group is larger than that of non- RIF with pET and npET group. This study further confirmed the clinical value of ERA in infertile patients with previous failed ET cycle, especially in RIF patients. Not only that, we also found that for patients with non-RIF, pET guided by ERA has a certain effect on reducing the early spontaneous abortion rate. This is a new discovery, indicating that the displacement of the implantation window may be related to early abortion. However, for RIF patients, pET did not have such an effect, we believe the possible reasons are that patients with RIF have numerous other factors that can lead to miscarriage, including factors such as aneuploidy [\u003cspan additionalcitationids=\"CR29 CR30\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. But we need to pay attention to another point of endometrial scraping, which is an intentional damage to the endometrium that is carried out with the aim of improving outcomes from fertility treatment or the chance of natural conception [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. So, the improvement in pregnancy outcomes may be related to endometrial scraping caused by endometrial biopsy during ERA test, but we cannot rule out the influence of this confounding factor, which is also the limitation of this article.\u003c/p\u003e \u003cp\u003eEmbryo implantation is a process in which the endometrium in receptive state interacted with functional embryos, then the trophoblast established close links with the decidualized endometrium, which is controlled by estrogen, progesterone and a large number of transcription factors [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In this complex physiological process, numerous of molecular mediators participate in the initial maternal-fetal interaction under the coordination of ovarian steroid hormones [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Although it is known that ovaries produce many steroids throughout the menstrual cycle, only E2 and P have been proven to be essential for inducing endometrial receptivity [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Studies have shown that the disorder of the sex hormone will affect the endometrial receptivity [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e], and low serum progesterone on day of transfer adversely impacts ongoing pregnancy rates in hormonally prepared single blastocyst frozen embryo transfer cycles [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. Progesterone in advance can reduce pregnancy rate [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. Research has confirmed that exposure of human endometrial epithelial cells to high levels of estrogen can lead to abnormal expression of many key implantation molecules [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Estradiol reduction adversely affect the embryo quality and clinical outcomes of IVF-ET [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. However, these studies did not combine estrogen and progesterone with gene expression profile. There are currently no reports linking endometrial receptivity testing with hormone analysis for research. In this study, we measured the serum estrogen and progesterone levels on P\u0026thinsp;+\u0026thinsp;5d, and compared the estrogen and progesterone levels between the normal and displaced WOI groups, but there is no difference between the two groups, and the logistic regression analysis also showed that the estrogen and progesterone levels were not linearly correlated with the displaced WOI. Therefore, we divided the E2/P values into tertiles for analysis, we found that the displaced WOI rate of the median group 4.46\u0026thinsp;\u0026lt;\u0026thinsp;E2/P\u0026thinsp;\u0026le;\u0026thinsp;10.39 pg/ng was significantly lower than that of the other two groups, which indicated that an appropriate E2/P ratio value was important for maintaining the endometrial receptivity state.\u003c/p\u003e \u003cp\u003eAge is an important influencing factor on pregnancy rate of assisted reproduction. There have some studies reported the relationship between advanced maternal age and decline of endometrial receptivity [\u003cspan additionalcitationids=\"CR43\" citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e], but all these reports studied the endometrial receptivity from the standpoint of pregnancy outcomes. So far, there has no studies combined age with the gene expression test of endometrial receptivity. Our study showed that there has a significant difference in age between the normal WOI and displaced WOI patients, and the results of logistic regression analysis also showed that age was positively correlated with displaced WOI. We divided all patients who received ERA test into three groups according to their age, we found that the displaced WOI rate increased gradually with the increase of age group, which indicated that as age increases, the occurrence probability of displaced WOI also gradually increases.\u003c/p\u003e \u003cp\u003eWe also found that there was a significant difference in the number of previous failed ET cycle between the normal WOI and displaced WOI patients, and the results of logistic regression analysis also showed that the number of previous failed ET cycle was positively correlated with the displaced WOI. According to the number of previous failed ET cycle, we divided the patients into three groups for detailed analysis, and we found that the displaced WOI rate increased gradually with the increase of the number of previous failed ET cycle. Our result showed that the higher the number of previous failed cycle, the greater the likelihood of displaced WOI in patients.\u003c/p\u003e \u003cp\u003ePsychological pressure and loss of hope for success are factors that must be taken seriously in the progress of assisted reproduction [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. According to reports, a surprising number of couples stop continuing treatment after at least one failed IVF cycle [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]. The cause of implantation failure is due partly to individual differences of WOI. According to our study, we suggest that positive actions including endometrial receptivity assessments are recommended to improve the outcomes of assisted reproduction for elderly patients and patients who have experienced one or more failed cycles.\u003c/p\u003e \u003cp\u003eAs our study suggests that the endometrial receptivity is influenced by some maternal factors, including age-time changes, hormonal changes, and there maybe has some other unknown factors. Due to the invasive examination of endometrial biopsy, embryo transfer cannot be performed during the biopsy cycle. So, the endometrial receptivity status during the biopsy cycle may differ from the actual embryo transfer cycle, which may also lead to different outcomes. We believe this may also be a reason for controversy regarding the application of ERA. Therefore, it is necessary to search for new non-invasive methods for ERA.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe clinical pregnancy rate and live birth rate of patients with previous failed ET cycle was improved after pET guided by ERA, especially in RIF patients; the early abortion rate of the non-RIF patient was reduced after pET guided by ERA. Moreover, we firstly found that an appropriate E2/P ratio is beneficial for maintaining endometrial receptivity state, and the probability of displacement WOI will increase with age and number of previous failed ET cycle.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eS.Y.X contributed to statistical analysis and interpretation of data and drafting of the manuscript. Y.Z and Y.Z.Z conceived and designed this study, performed statistical analysis and participated in the discussion. H.L.D and Y.X were involved in acquisition, analysis and interpretation of data. S.Y.X, YZ, C.J.Z and Y.Z.Z participated in the discussion and critically revised the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was supported by a research grant (No.81771543) from the National Natural Science Foundation of China.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData will be available on request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Ethics Committee of Renmin Hospital, Hubei University of Medicine (reference number: syrmyy2023-052) and conducted in conformity with the Helsinki Declaration. Written informed\u003c/p\u003e\n\u003cp\u003econsent was waived due to the retrospective nature, and patients\u0026rsquo; data were used anonymously.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAwonuga AO, Camp OG, Abu-Soud HM, et al. Determinants of Embryo Implantation: Roles of the Endometrium and Embryo in Implantation Success. Reprod Sci. 2023 Aug;30(8):2339-2348. \u003c/li\u003e\n\u003cli\u003eMassarotti C, Makieva S, Stigliani S. Editorial: Challenges in fertilization and implantation success. Front Cell Dev Biol. 2023 Aug 30;11:1268635.\u003c/li\u003e\n\u003cli\u003eCimadomo D, Capalbo A, Dovere L, et al. Leave the past behind: women\u0026apos;s reproductive history shows no association with blastocysts\u0026apos; euploidy and limited association with live birth rates after euploid embryo transfers. Hum Reprod. 2021 Mar 18;36(4):929-940. \u003c/li\u003e\n\u003cli\u003eHiraoka T, Osuga Y, Hirota Y. Current perspectives on endometrial receptivity: A comprehensive overview of etiology and treatment. J Obstet Gynaecol Res. 2023 Oct;49(10):2397-2409. \u003c/li\u003e\n\u003cli\u003eSebastian-Leon P, Devesa-Peiro A, Aleman A, et al. Transcriptional changes through menstrual cycle reveal a global transcriptional derepression underlying the molecular mechanism involved in the window of implantation. Mol Hum Reprod. 2021 May 8;27(5):gaab027.\u003c/li\u003e\n\u003cli\u003eBui AH, Timmons DB, Young SL. Evaluation of endometrial receptivity and implantation failure. Curr Opin Obstet Gynecol. 2022 Jun 1;34(3):107-113. \u003c/li\u003e\n\u003cli\u003ede Ziegler D, Scott RT Jr, Pirtea P. 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Fertil Steril. 2019 Oct;112(4 Suppl1):e81-e84.\u003c/li\u003e\n\u003cli\u003eD\u0026iacute;az-Gimeno P, Horcajadas JA, Mart\u0026iacute;nez-Conejero JA, et al. A genomic diagnostic tool for human endometrial receptivity based on the transcriptomic signature. Fertil Steril. 2011 Jan;95(1):50-60, 60.e1-15. \u003c/li\u003e\n\u003cli\u003eSun B, Yeh J. Non-Invasive and Mechanism-Based Molecular Assessment of Endometrial Receptivity During the Window of Implantation: Current Concepts and Future Prospective Testing Directions. Front Reprod Health. 2022 May 4;4:863173.\u003c/li\u003e\n\u003cli\u003eLiu Z, Liu X, Wang M, et al. The Clinical Efficacy of Personalized Embryo Transfer Guided by the Endometrial Receptivity Array/Analysis on IVF/ICSI Outcomes: A Systematic Review and Meta-Analysis. Front Physiol. 2022 Apr 27;13:841437.\u003c/li\u003e\n\u003cli\u003eSim\u0026oacute;n C, G\u0026oacute;mez C, Cabanillas S, et al. A 5-year multicentre randomized controlled trial comparing personalized, frozen and fresh blastocyst transfer in IVF. Reprod Biomed Online. 2020 Sep;41(3):402-415.\u003c/li\u003e\n\u003cli\u003eOhara Y, Matsubayashi H, Suzuki Y, et al. Clinical relevance of a newly developed endometrial receptivity test for patients with recurrent implantation failure in Japan. Reprod Med Biol. 2022 Feb 7;21(1):e12444. \u003c/li\u003e\n\u003cli\u003eChen J, He A, Zhang Q, et al. The RNA-seq based endometrial receptivity test (rsERT) compared to pinopode: A better diagnostic tool for endometrial receptivity for patients with recurrent implantation failure in Chinese population. Front Endocrinol (Lausanne). 2022 Oct 21;13:1009161.\u003c/li\u003e\n\u003cli\u003eHessami K, Khatibi A, Arian SE. Response letter to Endometrial receptivity array before frozen embryo transfer cycles: a systematic review and meta-analysis. Fertil Steril. 2023 May;119(5):892.\u003c/li\u003e\n\u003cli\u003eRichter KS, Richter ML. Personalized embryo transfer reduces success rates because endometrial receptivity analysis fails to accurately identify the window of implantation. Hum Reprod. 2023 Jul 5;38(7):1239-1244.\u003c/li\u003e\n\u003cli\u003eRiestenberg C, Kroener L, Quinn M, et al. Routine endometrial receptivity array in first embryo transfer cycles does not improve live birth rate. Fertil Steril. 2021 Apr;115(4):1001-1006.\u003c/li\u003e\n\u003cli\u003eGlujovsky D, Lattes K, Miguens M, et al. Personalized embryo transfer guided by endometrial receptivity analysis: a systematic review with meta-analysis. Hum Reprod. 2023 Jul 5;38(7):1305-1317.\u003c/li\u003e\n\u003cli\u003eLiu Z, Liu X, Li F, et al. Overexpression of hypoxia-inducible factor 1\u0026alpha; and excessive vascularization in the peri-implantation endometrium of infertile women with chronic endometritis. Front Endocrinol (Lausanne). 2022 Dec 1;13:1001437.\u003c/li\u003e\n\u003cli\u003eShan J, Li DJ, Wang XQ. Towards a Better Understanding of Endometriosis-Related Infertility: A Review on How Endometriosis Affects Endometrial Receptivity. Biomolecules. 2023 Feb 24;13(3):430.\u003c/li\u003e\n\u003cli\u003eHiraoka T, Osuga Y, Hirota Y. Current perspectives on endometrial receptivity: A comprehensive overview of etiology and treatment. J Obstet Gynaecol Res. 2023 Oct;49(10):2397-2409.\u003c/li\u003e\n\u003cli\u003eVon Woon E, Greer O, Shah N, et al. Number and function of uterine natural killer cells in recurrent miscarriage and implantation failure: a systematic review and meta-analysis. Hum Reprod Update. 2022 Jun 30;28(4):548-582.\u003c/li\u003e\n\u003cli\u003eVomstein K, Reider S, B\u0026ouml;ttcher B, et al. Uterine microbiota plasticity during the menstrual cycle: Differences between healthy controls and patients with recurrent miscarriage or implantation failure. J Reprod Immunol. 2022 Jun;151:103634.\u003c/li\u003e\n\u003cli\u003eStevens Brentjens L, Habets D, Den Hartog J, et al. Endometrial factors in the implantation failure spectrum: protocol of a MUltidisciplinary observational cohort study in women with Repeated Implantation failure and recurrent Miscarriage (MURIM Study). BMJ Open. 2022 Jun 8;12(6):e056714.\u003c/li\u003e\n\u003cli\u003eESHRE Working Group on Recurrent Implantation Failure; Cimadomo D, de Los Santos MJ, Griesinger G, Lainas G, Le Clef N, McLernon DJ, Montjean D, Toth B, Vermeulen N, Macklon N. ESHRE good practice recommendations on recurrent implantation failure. Hum Reprod Open. 2023 Jun 15;2023(3):hoad023.\u003c/li\u003e\n\u003cli\u003ePalomba S, Vitagliano A. Is the era of the endometrial scratching finished? Fertil Steril. 2022 Sep;118(3):603.\u003c/li\u003e\n\u003cli\u003eWong TY, Lensen S, Wilkinson J, et al. Effect of endometrial scratching on unassisted conception for unexplained infertility: a randomized controlled trial. Fertil Steril. 2022 Mar;117(3):612-619.\u003c/li\u003e\n\u003cli\u003eStevens Brentjens LBPM, Obukhova D, den Hartog JE, et al. An integrative analysis of endometrial steroid metabolism and transcriptome in relation to endometrial receptivity in in vitro fertilization patients. F S Sci. 2023 Aug;4(3):219-228.\u003c/li\u003e\n\u003cli\u003ePerry GA, Ketchum JN, Quail LK. Importance of preovulatory estradiol on uterine receptivity and luteal function. Anim Reprod. 2023 Sep 4;20(2):e20230061.\u003c/li\u003e\n\u003cli\u003eAl-Lamee H, Ellison A, Drury J, et al. Altered endometrial oestrogen-responsiveness and recurrent reproductive failure. Reprod Fertil. 2022 Feb 21;3(1):30-38.\u003c/li\u003e\n\u003cli\u003eParisi F, Fenizia C, Introini A, et al. The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester. Hum Reprod Update. 2023 Jun 23:dmad016.\u003c/li\u003e\n\u003cli\u003eShekhar B, Mittal S, Majumdar G, et al. Low serum progesterone on day of transfer adversely impacts ongoing pregnancy rates in hormonally prepared single blastocyst frozen embryo transfer cycles. Eur J Obstet Gynecol Reprod Biol. 2023 Oct;289:55-59.\u003c/li\u003e\n\u003cli\u003eGurunath S. Premature Progesterone Elevation in in vitro Fertilisation Cycles - Current Perspectives. J Hum Reprod Sci. 2022 Oct-Dec;15(4):325-336.\u003c/li\u003e\n\u003cli\u003eUllah K, Rahman TU, Pan HT, et al. Serum estradiol levels in controlled ovarian stimulation directly affect the endometrium. J Mol Endocrinol. 2017 Aug;59(2):105-119.\u003c/li\u003e\n\u003cli\u003eCheng J, Yang S, Ma H, Liang Y, Zhao J. Estradiol (E2) Reduction Adversely Affect the Embryo Quality and Clinical Outcomes of In Vitro Fertilization and Embryo transfer (IVF-ET). J Healthc Eng. 2022 Apr 7;2022:2473876.\u003c/li\u003e\n\u003cli\u003ePathare ADS, Loid M, Saare M, et al. Endometrial receptivity in women of advanced age: an underrated factor in infertility. Hum Reprod Update. 2023 Jul 19:dmad019.\u003c/li\u003e\n\u003cli\u003eShao Y, Feng H, Li L, Zong Y, Liang J. Predictive Value of Endometrial Receptivity for Pregnancy Outcomes of In-vitro Fertilization Embryo Transfer for Patients of Different Ages. Altern Ther Health Med. 2023 May;29(4):210-217.\u003c/li\u003e\n\u003cli\u003eZhao J, Huang B, Li N, et al. Relationship between advanced maternal age and decline of endometrial receptivity: a systematic review and meta-analysis. Aging (Albany NY). 2023 Feb 27;15(7):2460-2472.\u003c/li\u003e\n\u003cli\u003eSharma A, Shrivastava D. Psychological Problems Related to Infertility. Cureus. 2022 Oct 15;14(10):e30320.\u003c/li\u003e\n\u003cli\u003eKulkarni G, Mohanty NC, Mohanty IR, et al. Survey of reasons for discontinuation from in vitro fertilization treatment among couples attending infertility clinic. J Hum Reprod Sci. 2014 Oct-Dec;7(4):249-54.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 5 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Endometrial receptivity, Windows of implantation, Personalized embryo transfer, Implantation failure, E2/P ratio, Clinical pregnancy, Live birth","lastPublishedDoi":"10.21203/rs.3.rs-4374140/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4374140/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eThe endometrium in a receptive status is critical for a successful embryo implantation, but the receptivity of endometrium to embryos is only a short period of time, and the window of implantation (WOI) of each woman has individual variation, which will lead to poor outcomes of assisted reproduction. This so-called window of implantation can be detected by molecular diagnostic method, endometrial receptivity analysis (ERA), which was gradually applied to clinical practice. This study aimed to evaluate the clinical efficacy of personalized embryo transfer (pET) guided by ERA in patients with and without RIF, statistically analyze the clinical factors correlated with displaced WOI.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u0026nbsp;\u003c/strong\u003eA total of 3605 patients with previous failed embryo transfer (ET) cycle in the Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine from January 2016 to October 2022 were retrospectively analyzed. 3605 patients were divided into non-RIF group and RIF group, among them 782 patients who received ERA test underwent personalized embryo transfer (pET). The decision whether to accept ERA test or not was based on the patient's voluntary choice. We divided the 782 patients into normal WOI group and displaced WOI group according to the result of ERA test.\u003cstrong\u003e \u003c/strong\u003eThe pregnancy outcomes were compared between the different groups. The age, number of previous ET cycle and serum E2/P ratio were mainly analyzed to investigate its relationship with displaced WOI.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003eThe clinical pregnancy rate and live birth rate in non-RIF with pET group were higher than that of non-RIF with non-personalized embryo transfer (npET) group (64.5% vs 58.3%, P=0.025; 57.1% vs 48.3%, P=0.003). The clinical pregnancy rate and the live birth rate in RIF with pET group were significantly higher than that of RIF with npET group (62.7% vs 49.3%, P\u0026lt;0.001; 52.5% vs 40.4%, P\u0026lt;0.001) after propensity score matching (PSM). The early abortion rate in the non-RIF with pET group was lower than that in the non-RIF with npET group (8.2% vs 13.0%, P=0.038). There was a significant difference in age and the number of previous failed ET cycle between the normal WOI group and displaced WOI group (age:32.26 vs 33.53 years, P\u0026lt;0.001; the number of previous failed ET cycle:1.68 vs 2.04, P\u0026lt; 0.001). Logistic regression analysis also showed that the age and number of previous failed ET cycles were positively correlated with displaced WOI. The displaced WOI rate increased gradually with the increase of age and number of previous failed ET cycle; the displaced WOI rate in the median group 4.46\u0026lt;E2/P≤10.39 pg/ng was significantly lower than that in the other two groups (54.8% vs 40.6% vs 58.5%, P\u0026lt;0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003eThe clinical pregnancy rate and live birth rate of patients with previous failed ET cycle was improved after pET guided by ERA, especially in RIF patients; the early abortion rate of the non-RIF patient was reduced after pET guided by ERA. An appropriate E2/P ratio was beneficial for maintaining endometrial receptivity state, and the age and number of previous failed ET cycle was correlated with increased displaced WOI.\u003c/p\u003e","manuscriptTitle":"The clinical efficacy evaluation of endometrial receptivity analysis (ERA) and Study on the influence factors of displaced window of implantation (WOI): A 6-year retrospective study on a large sample","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-05-17 18:25:24","doi":"10.21203/rs.3.rs-4374140/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"785aaf6b-3971-42ed-8233-f02127dfd871","owner":[],"postedDate":"May 17th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-06-18T09:18:08+00:00","versionOfRecord":[],"versionCreatedAt":"2024-05-17 18:25:24","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4374140","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4374140","identity":"rs-4374140","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}