Endometrial thickness on the day of embryo transfer is a poor predictor of IVF treatment outcome

Increasing Endometrial Thickness Beyond 8 mm Does Not Alter Clinical Pregnancy Rate After Single Euploid Embryo Transfer

The aim of this study was to investigate if variation in endometrial thickness affects clinical pregnancy and live birth rates among patients undergoing single euploid embryo transfer (SET). A retrospective review of IVF cycles performed at a single private fertility institution between 2015 and 2020 was performed. Patients with normal uterine anatomy undergoing their first SET of a euploid embryo undergoing their first cycle at the center were included, for a total of 796 cycles. Endometrial thickness was measured by transvaginal ultrasound following 10-14 days of estradiol exposure. Specific infertility diagnoses did not significantly impact endometrial lining thickness with means across diagnoses ranging from 9.3 to 11.0 mm. Endometrial thickness was grouped into five categories: < 8 mm, 8-10 mm, 10-13 mm, 13-15 mm, and ≥ 15 mm. Using 8-10 mm as the reference group, the odds ratio of live birth was 0.5, 1.22, 1.05, and 1.05 for < 8 mm, 10-13 mm, 13-15 mm, and ≥ 15 mm groups, respectively. Risk of first trimester miscarriage was equivalent across groups. There was a trend toward an increased rate of biochemical pregnancies in patients with a < 8 mm and ≥ 15 mm endometrium; however, this was not statistically significant. The clinical pregnancy and live birth rate were lowest in patients with < 8-mm endometrial thickness. For single euploid embryo transfers, an endometrial lining greater than or equal to 8 mm confers optimal live birth rates following a medicated FET cycle. These data confirm the findings of prior studies in fresh embryo transfers without the confounders of supraphysiologic ovarian hormone concentrations and genetically untested embryos.

When the Embryo Meets the Endometrium: Identifying the Features Required for Successful Embryo Implantation

Evaluation of the optimal number of embryos, their quality, and the precise timing for transfer are critical determinants in reproductive success, although still remaining one of the main challenges in assisted reproduction technologies (ART). Indeed, the success of in vitro fertilization (IVF) treatments relies on a multitude of events and factors involving both the endometrium and the embryo. Despite concerted efforts on both fronts, the overall success rates of IVF techniques continue to range between 25% and 30%. The role of the endometrium in implantation has been recently recognized, leading to the hypothesis that both the "soil" and the "seed" play a central role in a successful pregnancy. In this respect, identification of the molecular signature of endometrial receptivity together with the selection of the best embryo for transfer become crucial in ART. Currently, efforts have been made to develop accurate, predictive, and personalized tests to identify the window of implantation and the best quality embryo. However, the value of these tests is still debated, as conflicting results are reported in the literature. The purpose of this review is to summarize and critically report the available criteria to optimize the success of embryo transfer and to better understand current limitations and potential areas for improvement.

Impact of endometrial compaction on reproductive outcomes after cryotransfer of euploid embryos in a modified natural cycle: protocol for a prospective cohort study

Introduction

Embryo implantation is a complex and poorly understood process. Most studies to date have focused on the analysis of the endometrium at the end of the estrogenic phase, while the available data on its importance after secretory transformation are limited and inconsistent. Current evidence does not allow for a conclusive interpretation of the changes observed in the pre-implantation endometrium, whether in the natural or replacement cycle, and their relevance in the development of a pregnancy or the implications for clinical practice.

Methods

Multicenter prospective observational cohort study. Based on our sample size calculation, the study group will consist of 206 women (exposed or "compaction" group: 103 women with a decrease of ≥ 5% in endometrial thickness between the estrogenic phase and the day of embryo transfer; non-exposed "non-compaction" group: 103 women with similar or greater endometrial thickness between these time points). The main objective of this study is to compare the ongoing pregnancy rates in natural cycles for euploid embryo transfer in patients who present endometrial compaction at the time of transfer versus those who with a stable or greater endometrial thickness with respect to the estrogenic phase. The estimated duration of the study is 30 months. Inclusion criteria are: 18 to 50 years of age, with primary or secondary infertility, subjected to endometrial preparation in a modified natural cycle for transfer of a genetically euploid blastocyst, from their own oocyte or oocyte donation, with a normal uterine cavity. Exclusion criteria are: uterine or endometrial disease (e.g., multiple myomatosis, severe adenomyosis, Asherman syndrome, refractory endometrium), conditions that prevent correct ultrasound assessment (tilted uterus), or a history of recurrent implantation failure or repeated miscarriages.

Discussion

The findings from this study will provide valuable insights into the potential influence of the "endometrial compaction" phenomenon on reproductive outcomes during natural cycle endometrial preparation. By examining this aspect, we aim to contribute to a better understanding of the factors that may impact successful outcomes in fertility treatments.

A critical appraisal of studies on endometrial thickness and embryo transfer outcome

A receptive endometrium is required for successful embryo implantation. Endometrial thickness, as measured by ultrasonography, is the most commonly used marker of endometrial receptivity in assisted reproductive technology cycles. Several factors simultaneously affect both endometrial thickness and probability of live birth, including age, oestradiol concentration and oocyte number, among others. Most of the studies investigating a relationship between endometrial thickness and embryo transfer outcomes are retrospective and do not adequately address confounding factors, in addition to other limitations. Despite multiple meta-analyses and studies with large numbers of cycles, controversy still exists. The difference between the results from prospective and retrospective studies is also striking. This article presents a critical appraisal of the studies on endometrial thickness and embryo transfer outcomes in order to highlight methodological issues and how they can be overcome in future studies. Currently available evidence does not seem to support a modification of management just because endometrial thickness is below an arbitrary threshold.

The use of real time strain endometrial elastosonography plus endometrial thickness and vascularization flow index to predict endometrial receptivity in IVF treatments: a pilot study

BACKGROUND

The usefulness of endometrium strain elastosonography (SE) for the evaluation of endometrial receptivity in women undergoing in vitro fertilization (IVF) remains controversial. The objective of this prospective, observational study was to evaluate the correlation between endometrial thickness (EMT) and its related strain (ESR) on the day of ovulation triggering (hCG-d) and in vitro fertilization outcomes. Additionally, 3D Power Doppler vascular indices (3DPDVI) were also analysed.

METHODS

We included all the patients undergoing fresh IVF-single blastocyst transfer cycle from January 2021 to August 2021 at our center. On hCG-d, after B-mode scanning was completed to measure the EMT, the mode was changed to elastosonography to evaluate the ESR (ratio between endometrial tissue and the myometrium below). At the end of examination, the Endometrial Volume (EV) and 3DPDVI (vascularization index [VI], flow index [FI] and vascularization flow index [VFI]), were assessed. Statistical analysis was completed using STATA MP16 software.

RESULTS

A total number of 57 women were included. Based on the EMT on hCG-d, women were divided into two groups, Group 1: <7 mm and Group 2 ≥ 7 mm. Women with EMT < 7 mm had a significantly higher ESR (p = 0.004) and lower pregnancy rate (p = 0.04). Additionally, low ESR values were correlated with high VFI values (rho = -0.8; 95% CI = -0.9- -0.6; p < 0.0001) and EMT ≥ 7 mm could be predicted by low ESR (OR = 0.01; 95% CI = 0.01-0.30; p = 0.008, area under the ROC curve: 0.70). After all, in multiple logistic regression analysis, low values of ESR (p = 0.050) and high values of EMT (p = 0.051) on hCG-d had borderline statistical effects on pregnancy rate.

CONCLUSIONS

The ESR may be useful to improve the ultrasound evaluation of the endometrial quality in infertile women candidates to IVF/ICS. Given the small sample size of our study, the usefulness of strain elastosonography in this patients, needs further investigation.

Suitable endometrial thickness on embryo transfer day may reduce ectopic pregnancy rate and improve clinical pregnancy rate

BACKGROUND

This retrospective study aimed to investigate the most suitable endometrial thickness (EMT) on the day of embryo transfer that could reduce ectopic pregnancy rate (EPR) and improve clinical pregnancy rate (CPR) in fresh embryo transfer patients with early follicular phase long-acting regimen.

METHODS

A total of 11,738 IVF/ICSI cycles, comprising 4,489 non-clinical pregnancies, 7,121 intrauterine pregnancies, and 128 ectopic pregnancy cycles after fresh embryo transfer, recorded between September 2017 and December 2020. Clinical pregnancy (CP) and ectopic pregnancy (EP) were the primary outcomes. Multivariate logistic regression was used to calculate the adjusted odds ratio (aOR) and 95% confidence interval (CI) for EP and CP. Patients were divided into three groups based on the EMT (6-10 mm, 11-15 mm, and 16-20 mm). CPR and EPR per millimeter of EMT were drawn into a line chart, and three groups were analyzed by Chi-square test.

RESULTS

After controlling for potential confounders, EMT had a significant effect on CP (aOR = 1.07; 95% CI, 1.05-1.08; P = 0.00) and EP (aOR = 0.88; 95% CI, 0.82-0.94; P = 0.00). With the increase of EMT, CPR increased and EPR decreased. Pearson correlation coefficients were r = 0.708 (P = 0.00) and r =-0.558 (P = 0.03), respectively. Significant differenceswere detected in the CPRs and EPRs (all P = 0.00). The CPR in the 6-10 mm group (54.88%) was significantly lower than that in the 11-15 mm group (64.23%) and the 16-20 mm group (64.40%) (P = 0.00). The EPR in the 6-10 mm group (2.72%) was significantly higher than that in the other two groups (1.60% and 0.97%, P = 0.00). The difference in CPR and EPR between the 11-15 mm group and the 16-20 mm group was not statistically significant, which indicated that EMT ≥ 11 mm simultaneously reduced the EPR and increased the CPR.

CONCLUSIONS

EMT was inversely proportional to EPR and directly proportional to CPR in fresh embryo transfer cycles. The EMT ≥ 11 mm on the day of embryo transfer could simultaneously achieve lower EPR and higher CPR. Accordingly, more attention should be given to the EMT of women who underwent ART treatment.

Endometrial compaction is associated with the increased live birth rate in artificial frozen-thawed embryo transfer cycles

We aimed to assess the effect of endometrial compaction on the live birth rate in frozen-thawed embryo transfer (FET) cycles and to investigate the parameters associated with compaction. FET cycles performed in a tertiary care infertility centre between May 2013 and October 2019 were reviewed retrospectively. The decremental change of endometrial thickness between the end of oestrogen phase and ET day was defined as endometrial compaction. The primary outcome measure was endometrial compaction, and the secondary outcome was the live birth rate. Among all, 89 had endometrial compaction and 194 did not. The live birth rate was significantly higher in the compaction group (23.6 vs. 13.4%, respectively; p = 0.039). Multivariate logistic regression analysis revealed that in FET cycles with artificial endometrial preparation, the chance for live birth was significantly higher in cycles with endometrial compaction [OR: 3.133, 95% confidence interval (CI) 1.104-8.892; p = 0.032] when adjusted for age, stage of the embryo, and endometrial thickness at the end of the oestrogen phase. According to receiver operating characteristic (ROC) curve analysis the sensitivity and specificity of 9.25 mm endometrial thickness at the end of oestrogen phase were 76.4 and 58.8%, respectively (area under the curve: 0.701, 95% CI 0.640-0.763; p < 0.001) to predict endometrial compaction.

ESHRE good practice recommendations on recurrent implantation failure

STUDY QUESTION

How should recurrent implantation failure (RIF) in patients undergoing ART be defined and managed?

SUMMARY ANSWER

This is the first ESHRE good practice recommendations paper providing a definition for RIF together with recommendations on how to investigate causes and contributing factors, and how to improve the chances of a pregnancy.

WHAT IS KNOWN ALREADY

RIF is a challenge in the ART clinic, with a multitude of investigations and interventions offered and applied in clinical practice, often without biological rationale or with unequivocal evidence of benefit.

STUDY DESIGN SIZE DURATION

This document was developed according to a predefined methodology for ESHRE good practice recommendations. Recommendations are supported by data from the literature, if available, and the results of a previously published survey on clinical practice in RIF and the expertise of the working group. A literature search was performed in PubMed and Cochrane focussing on 'recurrent reproductive failure', 'recurrent implantation failure', and 'repeated implantation failure'.

PARTICIPANTS/MATERIALS SETTING METHODS

The ESHRE Working Group on Recurrent Implantation Failure included eight members representing the ESHRE Special Interest Groups for Implantation and Early Pregnancy, Reproductive Endocrinology, and Embryology, with an independent chair and an expert in statistics. The recommendations for clinical practice were formulated based on the expert opinion of the working group, while taking into consideration the published data and results of the survey on uptake in clinical practice. The draft document was then open to ESHRE members for online peer review and was revised in light of the comments received.

MAIN RESULTS AND THE ROLE OF CHANCE

The working group recommends considering RIF as a secondary phenomenon of ART, as it can only be observed in patients undergoing IVF, and that the following description of RIF be adopted: 'RIF describes the scenario in which the transfer of embryos considered to be viable has failed to result in a positive pregnancy test sufficiently often in a specific patient to warrant consideration of further investigations and/or interventions'. It was agreed that the recommended threshold for the cumulative predicted chance of implantation to identify RIF for the purposes of initiating further investigation is 60%. When a couple have not had a successful implantation by a certain number of embryo transfers and the cumulative predicted chance of implantation associated with that number is greater than 60%, then they should be counselled on further investigation and/or treatment options. This term defines clinical RIF for which further actions should be considered. Nineteen recommendations were formulated on investigations when RIF is suspected, and 13 on interventions. Recommendations were colour-coded based on whether the investigations/interventions were recommended (green), to be considered (orange), or not recommended, i.e. not to be offered routinely (red).

LIMITATIONS REASONS FOR CAUTION

While awaiting the results of further studies and trials, the ESHRE Working Group on Recurrent Implantation Failure recommends identifying RIF based on the chance of successful implantation for the individual patient or couple and to restrict investigations and treatments to those supported by a clear rationale and data indicating their likely benefit.

WIDER IMPLICATIONS OF THE FINDINGS

This article provides not only good practice advice but also highlights the investigations and interventions that need further research. This research, when well-conducted, will be key to making progress in the clinical management of RIF.

STUDY FUNDING/COMPETING INTERESTS

The meetings and technical support for this project were funded by ESHRE. N.M. declared consulting fees from ArtPRED (The Netherlands) and Freya Biosciences (Denmark); Honoraria for lectures from Gedeon Richter, Merck, Abbott, and IBSA; being co-founder of Verso Biosense. He is Co-Chief Editor of Reproductive Biomedicine Online (RBMO). D.C. declared being an Associate Editor of Human Reproduction Update, and declared honoraria for lectures from Merck, Organon, IBSA, and Fairtility; support for attending meetings from Cooper Surgical, Fujifilm Irvine Scientific. G.G. declared that he or his institution received financial or non-financial support for research, lectures, workshops, advisory roles, or travelling from Ferring, Merck, Gedeon-Richter, PregLem, Abbott, Vifor, Organon, MSD, Coopersurgical, ObsEVA, and ReprodWissen. He is an Editor of the journals Archives of Obstetrics and Gynecology and Reproductive Biomedicine Online, and Editor in Chief of Journal Gynäkologische Endokrinologie. He is involved in guideline developments and quality control on national and international level. G.L. declared he or his institution received honoraria for lectures from Merck, Ferring, Vianex/Organon, and MSD. He is an Associate Editor of Human Reproduction Update, immediate past Coordinator of Special Interest Group for Reproductive Endocrinology of ESHRE and has been involved in Guideline Development Groups of ESHRE and national fertility authorities. D.J.M. declared being an Associate Editor for Human Reproduction Open and statistical Advisor for Reproductive Biomedicine Online. B.T. declared being shareholder of Reprognostics and she or her institution received financial or non-financial support for research, clinical trials, lectures, workshops, advisory roles or travelling from support for attending meetings from Ferring, MSD, Exeltis, Merck Serono, Bayer, Teva, Theramex and Novartis, Astropharm, Ferring. The other authors had nothing to disclose.

DISCLAIMER

This Good Practice Recommendations (GPR) document represents the views of ESHRE, which are the result of consensus between the relevant ESHRE stakeholders and are based on the scientific evidence available at the time of preparation. ESHRE GPRs should be used for information and educational purposes. They should not be interpreted as setting a standard of care or be deemed inclusive of all proper methods of care, or be exclusive of other methods of care reasonably directed to obtaining the same results. They do not replace the need for application of clinical judgement to each individual presentation, or variations based on locality and facility type. Furthermore, ESHRE GPRs do not constitute or imply the endorsement, or favouring, of any of the included technologies by ESHRE.

Observations on clinical assessment of endometrial receptivity

This brief review will examine the investigation of the endometrial cavity before embryo transfer using various techniques, including hysteroscopy, endometrial biopsy using immunohistochemistry and molecular microarray, and ultrasound imaging. All these investigative tools are presently subject to controversy and require large prospective controlled trials for validation. During embryo transfer, the occurrence of a retained embryo does not appear to have a negative impact on pregnancy outcome, and finally, consistent data indicate that physical activity immediately after embryo transfer has no impact on pregnancy outcome.

Predicting the probability of a live birth after a freeze-all based in vitro fertilization-embryo transfer (IVF-ET) treatment strategy

BACKGROUND

The predictors for live birth rate (LBR) following one episode of in vitro fertilization (IVF) cycle for patients using a "freeze-all" strategy are not entirely clear.

METHODS

A retrospective cohort study utilizing a prediction model was developed to assess the relationship to the LBR. Women undergoing IVF with a freeze-all strategy were screened. Univariate models were first fitted for female age at oocytes retrieval/frozen-thawed embryo transfer (FET), body mass index (BMI), duration and etiology of infertility, previous IVF failures, total dose and duration of gonadotrophin, ovarian sensitivity index (OSI), number of oocytes collected, method of fertilization, number of embryos created, number and stage of embryos frozen, type and number of FET cycles, endometrial thickness (EMT)/pattern, hormone level on transplantation day, storage duration, number of embryos thawed and damaged thawed embryos, number and stage of embryos transferred and number of different quality embryos transferred. Variables with P<0.05 in the univariate model were selected for further analysis of the final multivariate discrete-time logistic regression model.

RESULTS

A total of 7,602 women undergoing one ovarian stimulation resulted in 9,964 FETs, of whom 3,066 (40.33%) had a live-birth after their first FET and 3,929 (51.68%) after total FETs. The EMT and woman's age at oocyte retrieval were the most important predictors. In the first FET, the LBR of women with an EMT ≤8 mm [27.40%; 95% confidence interval (CI): (21.60-33.81%)] was significantly lower than that of women with EMT between 9 and 11 mm [36.51%; 95% CI: (34.25-38.81%)] and thicker than 12 mm [44.23%; 95% CI: (42.22-46.25%)] (P<0.05). The optimistic and conservative cumulative LBRs of women younger than 31 years [87.5%; 95% CI: (86.32-88.61%) and 63.04%; 95% CI: (61.36-64.69%)] were significantly decreased in women aged 31-35, 36-40 and >40 (P<0.001).

CONCLUSIONS

Our study provides an effective prediction model for a woman's chance of having a baby after a "freeze-all" policy. The use of EMT and female age as tools to identify LBR are shown to be justified, and repeated FETs cannot reverse the age-dependent decline in fertility.

Frozen Blastocyst Embryo Transfer: Comparison of Protocols and Factors Influencing Outcome

Background: Various factors, including treatment protocols, can influence the outcomes of frozen embryo transfers (FETs). The study objectives were to compare different endometrial preparation protocols of FET cycles and to evaluate the factors, including the endometrial thickness (ET), that affect outcomes. Methods: This observational cohort study involved 5037 women undergoing FETs at eight tertiary clinics in the UK between January 2016 and March 2019. The endometrial preparation protocols used were natural cycle (NC-FETs), artificial hormone support cycle with oestradiol valerate but without pituitary downregulation (AC-FETs) and artificial hormone support cycle with agonist downregulation (ACDR-FETs). Results: The mean (±SD) ages across NC-FET, AC-FET and ACDR-FET groups were 36.5 (±4.2), 35.9 (±5.0) and 36.4(±4.9) years, respectively. LBRs were comparable (40.7%, 175/430; 36.8%, 986/2658; and 36.7%, 716/1949, respectively) across the three groups. Clinical pregnancy, implantation, multiple pregnancies, miscarriage and ectopic pregnancy rates were also similar. In the regression analysis of variables including age, duration of infertility, number of embryos transferred, protocol type and endometrial thickness, age was the only significant predictor of LBRs, although its predictive ability was poor (AUC: 0.55). With the overall LBR of the study population being 37.1%, the post-test probability of a live birth at an ET of <5 mm was 0%, and at 5–5.9, 6–6.9, 7–7.9 and 8–8.9 mm, the probabilities were 16.7%, 33.8%, 36.7% and 37.7%, respectively. The LBR remained above 35% up to the 14–14.9 mm range and then declined gradually to 23% for the 17–25 mm range. Conclusions: The FET outcomes were similar for the three protocols used for endometrial preparation. The protocol type and endometrial thickness were not predictive of FET outcomes; age was the only predictive variable, despite its low predictive ability.

Effect of endometrial thickness changes on clinical pregnancy rates after progesterone administration in a single frozen-thawed euploid blastocyst transfer cycle using natural cycles with luteal support for PGT-SR- and PGT-M-assisted reproduction: a retrospective cohort study

BACKGROUND

To investigate whether the endometrial thickness change ratio from the progesterone administration day to the blastocyst transfer day is associated with pregnancy outcomes in a single frozen-thawed euploid blastocyst transfer cycle.

METHODS

All patients used natural cycles with luteal support for endometrial preparation and selected a single euploid blastocyst for transfer after a biopsy for preimplantation genetic testing. The endometrial thickness was measured by transvaginal ultrasound on the progesterone administration day and the transfer day, the change in endometrial thickness was measured, and the endometrial thickness change ratio was calculated. According to the change rate of endometrial thickness, the patients were divided into three groups: the endometrial thickness compaction group, endometrial thickness non-change group and endometrial thickness expansion group. Among them, the endometrial thickness non-change and expansion groups were combined into the endometrial thickness noncompaction group.

RESULTS

Ultrasound images of the endometrium in 219 frozen-thawed euploid blastocyst transfer cycles were evaluated. The clinical pregnancy rate increased with the increase in endometrial thickness change ratio, while the miscarriage rate and live birth rate were comparable among the groups. The multiple logistic regression results showed that in the fully adjusted model a higher endometrial thickness change ratio (per 10%) was associated with a higher clinical pregnancy rate (adjusted odds ratio [aOR] 1.29; 95% confidence interval [CI], 1.01-1.64; P = .040). Similarly, when the patients were divided into three groups according to the change rate of endometrial thickness, the endometrial thickness noncompaction group had a significant positive effect on the clinical pregnancy rate compared with the endometrial thickness compaction group after adjusting for all covariates.

CONCLUSIONS

In frozen-thawed euploid blastocyst transfer cycles in which the endometrium was prepared by natural cycles with luteal support, the clinical pregnancy rate was higher in cycles without endometrial compaction after progesterone administration.

The change in endometrial thickness following progesterone exposure correlates with in vitro fertilization outcome after transfer of vitrified-warmed blastocysts

PURPOSE

To determine if the change in endometrial thickness following exogenous progesterone (P) initiation correlates with outcome following autologous transfer of a single thawed blastocyst.

METHODS

The study is a retrospective observational cohort study conducted at a private fertility center. Patients scheduled for thawed blastocyst transfer received artificial endometrial preparation (artificial cycle FET) and underwent serial ultrasonography. The main outcomes were the rate of ongoing pregnancy (fetal heart motion at 12 weeks of gestation) and early pregnancy loss. Logistic regression was used to test for correlations between these outcomes and the change in endometrial thickness while adjusting for potential confounders (patient age, embryo quality, and the use of genetic testing).

RESULTS

There were 232 qualifying autologous single-blastocyst transfers in the 20-month study period ending 31 December 2019. Mean endometrial thicknesses were 3.8 mm, 10.0 mm, and 11.2 mm at baseline, P initiation, and at transfer, respectively. The change in endometrial thickness after exogenous P exposure ranged from - 5 to + 9 mm and negatively correlated with ongoing pregnancy in logistic regression analyses. Specifically, ongoing pregnancy rates per transfer were 63.2% in 19 cases where endometria compacted by 10% or more, 64.2% in 95 cases where there was unchanged endometrial thickness, and 52.5% in 118 cases where endometria expanded.

CONCLUSIONS

The change in endometrial thickness after P initiation was associated with the probability of ongoing pregnancy but not with early pregnancy loss. Ongoing pregnancy rates were greater in endometria with negative growth (compaction) when compared to endometria that grew (expanded) after P exposure.

Sildenafil Supplementation for Women Undergoing Infertility Treatments: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The aim of this systematic review and meta-analysis is to summarize data on the effectiveness of Sildenafil supplementation for women undergoing assisted reproduction techniques. This meta-analysis of randomized controlled trials (RCTs) evaluates the effects of Sildenafil administration during infertility treatments compared with a control group in infertile women. Outcomes evaluated were endometrial thickness (ETh) and the clinical pregnancy rate (CPR). The chemical pregnancy rate (ChPR) was also evaluated. Pooled results were expressed as the risk ratio (RR) or mean differences (MD) with a 95% confidence interval (95% CI). Women undergoing ovulation induction who received Sildenafil showed higher ETh and a higher CPR in comparison to controls. In this group, both the ETh and ChPR resulted in significantly higher values only with delayed start administration. Women undergoing fresh or frozen embryo transfer who received Sildenafil showed no significant advantages regarding ETh and CPR in comparison to controls. In this group, we found a significantly higher ChPR in women receiving Sildenafil. A subgroup analysis revealed significant advantages regarding ETh with oral administration for women undergoing fresh or frozen embryo transfer. Sildenafil therapy appears to improve endometrial thickness and pregnancy rate in women undergoing timed intercourses but it resulted not effective in IUI and IVF treatments. Further RCTs with rigorous methodology are still mandatory.

Endometrial thickness changes after progesterone administration do not affect the pregnancy outcomes of frozen-thawed euploid blastocyst transfer: a retrospective cohort study

OBJECTIVE

To evaluate whether the change in endometrial thickness from progesterone administration day to transfer day is related to pregnancy outcomes in single frozen-thawed euploid blastocyst transfer cycles.

DESIGN

Observational cohort study.

SETTING

Single reproductive medical center.

PATIENT(S)

All patients were transferred with a single biopsied euploid blastocyst, and their endometrium was prepared with hormone replacement therapy (HRT).

INTERVENTION(S)

The endometrial thickness on the day of blastocyst transfer and progesterone administration was measured by transvaginal ultrasound, and the difference between them and the change ratio were calculated.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rates and live birth rates.

RESULT(S)

Endometrial ultrasound images of 508 euploid blastocyst transfer cycles using HRT were evaluated by transvaginal ultrasound. Overall, pregnancy outcomes were comparable in different groups of endometrial thickness changes. The results of multiple logistic regression showed that the clinical pregnancy rate and live birth rate did not significantly increase with the increase in endometrial thickness change ratios (per 10%) in the fully adjusted model as a continuous variable. In the adjustment model as a categorical variable, there was no statistical difference in pregnancy outcomes among the groups with changes in endometrial thickness. Interaction analysis showed that after adjusting for confounders, there was no statistically significant interaction between the endometrial thickness change ratio and pregnancy outcomes in all subgroups.

CONCLUSION(S)

In the euploid blastocyst transfer cycle of preparing the endometrium with HRT, the endometrial thickness change ratio after progesterone administration was not related to pregnancy outcomes.

The Disorders of Endometrial Receptivity in PCOS and Its Mechanisms

Polycystic ovary syndrome (PCOS) is a mysterious and complicated endocrine disease with the combination of metabolic, reproductive, psychological dysfunctions. Impaired endometrial receptivity and ovulation disorders/anovulation are both important causes of PCOS-related infertility. However, change in endometrium has never received the same attention as ovulatory dysfunction. Besides, putting emphasis on endometrial function may be more realistic for PCOS-related infertility, given the wide use of assisted reproductive technology. The present review focuses on the disorders of endometrial receptivity of patients with PCOS, summarizes the changes of the indicators of endometrial receptivity including leukemia inhibitory factor, homeobox genes A, pinopodes, αvβ3-integrin, and intercellular junctions and also analyzes the possible mechanisms of decreased endometrial receptivity and its relationship with the main endocrine and metabolic disorders of PCOS such as hyperandrogenism, inflammation, insulin resistance, and obesity. Despite several biomarkers have been found to be associated with decreased endometrial receptivity in PCOS, the clinical relevance of these findings still awaits future clarification.

Endometrial thickness measurements among Asherman syndrome patients prior to embryo transfer

STUDY QUESTION

Is there an association between endometrial thickness (EMT) measurement and clinical pregnancy rate among Asherman syndrome (AS) patients utilizing IVF and embryo transfer (ET)?

SUMMARY ANSWER

EMT measurements may not be associated with successful clinical pregnancy among AS patients undergoing IVF.

WHAT IS KNOWN ALREADY

Clinical pregnancy rate after IVF is significantly lower in patients with a thin endometrium, defined as a maximum EMT of <7 mm. However, AS patients often have a thin EMT measurement due to intrauterine scarring, with a paucity of data and no guidance on what EMT cutoff is appropriate when planning an ET among these patients.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort study of 45 AS patients treated at a specialized advanced hysteroscopic clinic from 1 January 2015, to 1 March 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Review of EMT measurements prior to a total of 90 ETs, among 45 AS patients. The impact of the maximum EMT measurement prior to ET on clinical pregnancy rate was analyzed.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 25/45 (55.6%) AS patients ultimately went on to have ≥1 clinical pregnancy following a mean ± SD of 2.00 ± 1.26 ET attempts. There was a total of 90 ETs among the 45 AS patients, with 29/90 (32.2%) ETs resulting in a clinical pregnancy. Younger patient age (P = 0.05) and oocyte donation (P = 0.01) were the only variables identified to be significant predictors for a positive clinical pregnancy outcome on bivariate analysis. The mean EMT measurement prior to all ETs among AS patients was 7.5 ± 1.6 mm. EMT measurement prior to ET did not predict a positive clinical pregnancy on either bivariate (P = 0.84) or multivariable analysis (odds ratio 0.91, P = 0.60). 31.8% of EMT measurements measured <7.0 mm. In this small cohort, no difference in the clinical pregnancy rate was detected when comparing ETs with EMT measurements of <7.0 mm versus ≥7.0 mm (P = 0.83). The mean EMT measurement decreased with increasing AS disease severity; 8.0 ± 1.6 mm for mild disease, 7.0 ± 1.4 mm for moderate disease and 5.4 ± 0.1 mm for severe disease.

LIMITATIONS, REASONS FOR CAUTION

Our small sample size limits our ability to draw any definitive conclusions. In addition, patients utilized various infertility clinics. This limits our ability to evaluate the consistency of EMT measurements and the IVF care that was received.

WIDER IMPLICATIONS OF THE FINDINGS

EMT measurement cutoff values should be used with caution if canceling a scheduled ET in AS patients.

STUDY FUNDING/COMPETING INTEREST(S)

This study was not funded. K.I. reports personal fees from Karl Stroz and personal fees from Medtronics outside the submitted work. The other authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Endometrial thickness is not predictive for live birth after embryo transfer, even without a cutoff

OBJECTIVE

To investigate the predictive value of endometrial thickness (EMT) for live birth when a lower threshold of EMT is not employed for embryo transfer (ET).

DESIGN

Retrospective study SETTING: Academic assisted reproduction center PATIENT(S): All women who underwent fresh or frozen-thawed ET at the Koç University Hospital Assisted Reproduction Unit between October 2016 and August 2019 INTERVENTION(S): After ruling out endometrial pathology, blastocyst transfer was planned regardless of the EMT in the absence of increased serum progesterone level on the trigger day in fresh embryo transfer cycles or before commencing progesterone treatment in artificially prepared frozen-thawed ET cycles.

MAIN OUTCOME MEASURE(S)

The primary outcome was live birth. Live birth and miscarriage rates per ET were stratified according to fresh and frozen-thawed ET cycles for each millimeter of endometrial thickness. Receiver operator characteristic curve analyses were performed to evaluate the predictive value of EMT for live birth.

RESULT(S)

A total of 560 ET cycles, 273 fresh and 287 frozen-thawed, were included in the study. Relevant patient characteristics as well as EMTs were similar between women who achieved a live birth and those who did not after fresh or frozen-thawed ET. There was no linear association between EMT and live birth or miscarriage rates. Area under the curve values for EMT to predict live birth after fresh, frozen-thawed, and all ETs were 0.56, 0.47, and 0.52, respectively.

CONCLUSION(S)

Our results showed that the EMT was not predictive for live birth in either fresh or frozen-thawed ET cycles. Once intracavitary pathology and inadvertent progesterone exposure were excluded, women with thinner EMTs should not be denied their potential for live birth because it is comparable to that of those with thicker EMT.

Endometrial thickness on the day of the LH surge: an effective predictor of pregnancy outcomes after modified natural cycle-frozen blastocyst transfer

STUDY QUESTION

Can the endometrial thickness (EMT) on the day of the LH surge predict pregnancy outcomes after single vitrified-warmed blastocyst transfers (SVBTs) in modified natural cycles?

SUMMARY ANSWER

Decreased EMT on the day of the LH surge is associated with older female age and a shortened proliferation phase and may be associated with low live birth and high chemical pregnancy rates.

WHAT IS KNOWN ALREADY

The relation between EMT on the day of embryo transfer (ET) and pregnancy outcomes remains controversial; although numerous studies reported an association between decreased EMT on the day of ET and a reduced likelihood of pregnancy, recent studies demonstrated that the EMT on the day of ET had limited independent prognostic value for pregnancy outcomes after IVF. The relation between EMT on the day of the LH surge and pregnancy outcomes after SVBT in modified natural cycles is currently unknown.

STUDY DESIGN, SIZE, DURATION

In total, 808 SVBTs in modified natural cycles, performed from November 2018 to October 2019, were analysed in this retrospective cohort study. Associations of EMT on the days of the LH surge with SVBT and clinical and ongoing pregnancy rates were statistically evaluated. Clinical and ongoing pregnancy rates were defined as the ultrasonographic observation of a gestational sac 3 weeks after SVBTs and the observation of a foetal heartbeat 5 weeks after SVBTs, respectively. Similarly, factors potentially associated with the EMT on day of the LH surge, such as patient and cycle characteristics, were investigated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study includes IVF/ICSI patients aged 24–47 years, who underwent their first SVBT in the study period. After monitoring follicular development and serum hormone levels, ovulation was triggered via a nasal spray containing a GnRH agonist. After ovulation was confirmed, SVBTs were performed on Day 5. The EMT was evaluated by transvaginal ultrasonography on the day of the LH surge and immediately before the SVBT procedure.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the original 901 patients, 93 who were outliers for FSH or proliferative phase duration data were excluded from the analysis. Patients were classified according to quartiles of EMT on day of the LH surge, as follows: EMT < 8.1 mm, 8.1 mm ≤ EMT < 9.1 mm, 9.1 mm ≤ EMT < 10.6 mm and EMT ≥ 10.6 mm. Decreased EMT on day of the LH surge was associated with lower live birth (P = 0.0016) and higher chemical pregnancy (P = 0.0011) rates. Similarly, patients were classified according to quartiles of EMT on day of the SVBT, as follows: EMT < 9.1 mm, 9.1 mm ≤ EMT < 10.1 mm, 10.1 mm ≤ EMT < 12.1 mm and EMT ≥ 12.1 mm. A decreased EMT on the day of SVBT was associated with a lower live birth rate (P = 0.0095) but not chemical pregnancy rate (P = 0.1640). Additionally, multivariate logistic regression analysis revealed a significant correlation between EMT on day of the LH surge and ongoing pregnancy; however, no correlation was observed between EMT on the day of SVBT and ongoing pregnancy (adjusted odds ratio 0.952; 95% CI, 0.850–1.066; P = 0.3981). A decreased EMT on day of the LH surge was significantly associated with greater female age (P = 0.0003) and a shortened follicular/proliferation phase (P < 0.0001).

LIMITATIONS, REASONS FOR CAUTION

The data used in this study were obtained from a single-centre cohort; therefore, multi-centre studies are required to ascertain the generalisability of these findings to other clinics with different protocols and/or patient demographics.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first report demonstrating a significant correlation between EMT on day of the LH surge and pregnancy outcomes after frozen blastocyst transfer in modified natural cycles. Our results suggest that EMT on day of the LH surge may be an effective predictor of the live birth rate.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by resources from the Kato Ladies Clinic. The authors have no conflicts of interest to declare.

Endometrial compaction does not predict live birth rate in single euploid frozen embryo transfer cycles

PURPOSE

To evaluate whether endometrial compaction using sequential transvaginal ultrasound is associated with improved live birth rates in medicated single euploid frozen embryo transfer (FET) cycles.

METHODS

Prospective observational cohort study at a private fertility clinic. Patients who underwent FETs between January and December 2018 were assessed for inclusion. The change in endometrial thickness between the end of the estrogen phase and the day before embryo transfer, measured by sequential transvaginal ultrasound, was used to categorize cycles with compaction (≥ 5%), no change, or expansion (≥ 5%). FET cycle outcomes were then compared between groups. The primary outcome was live birth. Secondary outcomes include clinical pregnancy rate and rate of spontaneous abortion.

RESULTS

Of the 259 single euploid medicated FETs performed during the study period, only 43/259 (16.6%) of the cycles demonstrated ≥ 5% compaction, whereas 152/259 (58.7%) expanded and 64/259 (24.7%) were unchanged. Live birth rates did not differ between cycles with compaction (58.1%), no change (54.7%), or expansion (58.6%), p = 0.96. Clinical pregnancy and spontaneous abortion rates were also similar between groups.

CONCLUSION

The vast majority of cycles did not demonstrate endometrial compaction. Endometrial compaction is not associated with live birth rate or spontaneous abortion rate in medicated single euploid FETs in this cohort.

Endometrial Thickness Is a Risk Factor for Singleton Low Birth Weight From Single Blastocyst Transfer: A Retrospective Cohort Study

OBJECTIVE

To explore whether endometrial thickness (EMT) ≤7.5 mm is associated with singleton low birth weight (LBW) from single fresh blastocyst transfer.

METHODS

This was a retrospective cohort study. Only women ≤ 40 years old who underwent single fresh blastocyst transfer and had singleton live births were included in the study. LBW was the primary outcome of this study. Neonatal malformation was the secondary outcome. Logistic regression was used to evaluate the association between (EMT) ≤7.5 mm and singleton LBW.

RESULTS

A total number of 2847 women met the study inclusion criteria. The neonatal birthweight in the EMT ≤7.5 mm group was significantly lower than that in the EMT 7.6~12.0 mm and EMT >12.0 mm group (P<0.001). The rate of LBW in the EMT ≤7.5 mm group was 24.9%, which was significantly higher than the 4.0% in the EMT 7.6~12.0 mm group and the 5.3% in the EMT >12.0 mm group (P<0.001). The total neonatal malformation rate was similar between the groups (1.1%, 0.8% and 1.5%, P=0.21). After logistic regression analysis, EMT ≤7.5 mm was found to be an independent risk factor for LBW (adjusted odds ratio [AOR]: 4.39, 95% CI: 1.85_˜10.46, P<0.001).

CONCLUSION

EMT ≤7.5 mm on the hCG trigger day is an independent risk factor for LBW in singleton pregnancies from single fresh blastocyst transfer. The neonatal birthweight in the EMT ≤7.5 mm group was significantly lower than that in the EMT 7.6~12.0 mm and EMT >12.0 mm groups. The total neonatal malformation rate was comparable between the groups.

Interactions of Cortisol and Prolactin with Other Selected Menstrual Cycle Hormones Affecting the Chances of Conception in Infertile Women

One of the major problems of success in infertility treatment could depend on the understanding how the potential factors may affect the conception. The aim of this study was to evaluate present understanding of such factors or hormonal causes that may induce infertility. We studied the interactions between the two menstrual cycle hormones i.e., cortisol (COR) and prolactin (PRL), along with the ultrasonographic ovulation parameters in a group of N = 205 women with diagnosed infertility. The control group consisted of N = 100 women with confirmed fertility. In both groups, follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Müllerian hormone (AMH), thyroid stimulating hormone (TSH), PRL, COR were examined on the third day of the cycle, and estradiol (E2), progesterone (P), and COR were examined during ovulation and 7-days afterwards. In the infertile group, higher levels of PRL and COR were observed than that of in the control group. Cortisol levels at all phases of the menstrual cycle and PRL negatively correlated with E2 secretion during and after ovulation, thus contributed to the attenuation of the ovulatory LH surge. Infertile women who conceived presented with higher levels of E2 during and after ovulation, higher P after ovulation, and thicker endometrium than that of the women who failed to conceive. In conclusion, elevated secretion of COR and PRL in infertile women impairs the menstrual cycle by decreasing the pre-ovulatory LH peak and E2 and postovulatory E2 levels that affect the endometrial growth, and consequently reduce the chances to conceive.

Can Ratios Between Prognostic Factors Predict the Clinical Pregnancy Rate in an IVF/ICSI Program with a GnRH Agonist-FSH/hMG Protocol? An Assessment of 2421 Embryo Transfers, and a Review of the Literature

None of the models developed in in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) is sufficiently good predictors of pregnancy. The aim of this study was to determine whether ratios between prognostic factors could predict the clinical pregnancy rate in IVF/ICSI. We analyzed IVF/ICSI cycles (based on long GnRH agonist-FSH protocols) at two ART centers (the second to validate externally the data). The ratios studied were (i) the total FSH dose divided by the serum estradiol level on the hCG trigger day, (ii) the total FSH dose divided by the number of mature oocytes, (iii) the serum estradiol level on the trigger day divided by the number of mature oocytes, (iv) the serum estradiol level on the trigger day divided by the endometrial thickness on the trigger day, (v) the serum estradiol level on the trigger day divided by the number of mature oocytes and then by the number of grade 1 or 2 embryos obtained, and (vi) the serum estradiol level on the trigger day divided by the endometrial thickness on the trigger day and then by the number of grade 1 or 2 embryos obtained. The analysis covered 2421 IVF/ICSI cycles with an embryo transfer, leading to 753 clinical pregnancies (31.1% per transfer). Four ratios were significantly predictive in both centers; their discriminant power remained moderate (area under the receiver operating characteristic curve between 0.574 and 0.610). In contrast, the models' calibration was excellent (coefficients: 0.943-0.978; p < 0.001). Our ratios were no better than existing models in IVF/ICSI programs. In fact, a strongly discriminant predictive model will be probably never be obtained, given the many factors that influence the occurrence of a pregnancy.

The entire range of trigger-day endometrial thickness in fresh IVF cycles is independently correlated with live birth rate

RESEARCH QUESTION

What is the association of the entire range of trigger-day endometrial thickness (EMT) with live birth rate (LBR) after IVF and fresh embryo transfer? Although EMT is amenable to convenient non-invasive routine measurement, studies of the association between pre-trigger EMT and assisted reproductive technology outcome have yielded equivocal results.

DESIGN

A cohort of IVF fresh day-3 embryo transfers in patients aged 42 years and younger in a single centre between 2009 and 2017. The LBR was calculated for all trigger-day EMT values, stratified into five groups overall and within subgroups of patient age and ovarian response. Univariate analysis and multivariate logistic regression models were used to compare the LBRs at different EMT measurements adjusting for various independent variables.

RESULTS

A total of 5133 cycles were included. The LBRs were as follows: 11.22% (35/312) in cycles with EMT 6 mm or less, 17.98% (380/2114) in cycles with EMT 7-9 mm, 23.44% (476/2031) in cycles with EMT 10-12 mm, 25.62% (144/562) in cycles with EMT 13-15 mm and 34.21% (39/114) in cycles with EMT 16 mm or more (P < 0.001). Similar findings were observed by patient age and ovarian response. The observation was confirmed by multivariate logistic regression analysis in which the EMT was found to be a significant independent predictor of LBR even after controlling for various confounders (OR 0.935, 95% CI 0.908 to 0.962; P < 0.001).

CONCLUSIONS

Pre-trigger EMT is in significant independent correlation with LBR, even after adjusting for age and ovarian response. Maximal endometrial proliferation is beneficial, and fresh embryo transfer can be carried out at high EMT values without endangering the outcome of the cycle.

Cumulative Live Birth Rate in Patients With Thin Endometrium: A Real-World Single-Center Experience

Background: Studies have shown that patients with a thin endometrial thickness (EMT < 7 or 8 mm) during IVF/ICSI tend to have adverse pregnancy outcomes, and this has caused much anxiety to both patients and physicians when confronted with a thin EMT. Method: From January 2015 to December 2018, patients with a thin EMT < 7 mm on the day of hCG administration during their first GnRH agonist IVF/ICSI cycle were included. According to the hysteroscopy results, patients were classified into totally normal (Group A), normal with a specific abnormality (Group B), and adhesion before transfer (Group C). Result: For the 245 patients included, approximately 60% of the thin EMT cases were the result of an intrauterine operation. CLBR was 35.45% (67/189) in this group of patients. In regard to CLBR, there were significant differences among these three uterus condition groups irrespective of the number of oocytes retrieved (28.57 vs. 10.00 vs. 4.76%, P = 0.12 in oocyte ≤5; 61.36 vs. 44.67 vs. 23.63%, P = 0.00 in oocyte >5). In binary logistic regression analysis, age (OR = 0.09, P = 0.03), number of embryos available (OR = 1.71, P = 0.00), and uterine condition (OR = 6.77, P = 0.00 for group A; OR = 2.55, P = 0.04 for group B; Reference = group C), were significantly associated with CLBR. However, EMT and endometrial pattern had no impact on CLBR. Conclusion: An intrauterine operation was the main reason for a thin EMT. Thin EMT patients with a normal uterine cavity and endometrium had a significantly better CLBR compared with those with adhesions before transfer.

Effect of Endometrial Thickness Change in Response to Progesterone Administration on Pregnancy Outcomes in Frozen-Thawed Embryo Transfer: Analysis of 4465 Cycles

OBJECTIVE

To evaluate whether endometrial thickness (EMT) change in response to progesterone has an effect on pregnancy outcomes in frozen-thawed embryo transfer (FET) cycles.

DESIGN

Retrospective observational study.

SETTING

Tertiary-care academic medical center.

PARTICIPANTS

4465 infertile women undergoing their first FET between January 2010 and December 2015 in our center.

METHODS

This observational study included 4465 patients undergoing their first FET cycles between January 2010 and December 2015. EMT was measured by transvaginal ultrasound one day before progesterone administration and on the day of FET to observe EMT change.

MAIN OUTCOME MEASURES

Clinical pregnancy rate (CPR) and the live birthrate (LBR) was discussed.

RESULTS

Regardless of the endometrial preparation protocols such as artificial cycle, estrogen-progesterone replacement therapy (EP) or natural cycle (NC), EMT may increase, decrease or remain stable on the day of FET compared with that of one day before progesterone administration. CPR in EMT increase, decrease and stable groups were 48.4%, 51.3% and 50.7% in EP cycle versus 49.2%, 52.0% and 48.9% in NC cycle, showing no significant difference between the three groups in both cycles (P= 0.48, P= 0.49). LBR was 40.9%, 45.9% and 42.6% in EP cycle versus 44.2%, 44.8% and 42.1% in NC cycle, also showing no significant difference between the three groups in both cycles (P= 0.16, P= 0.66). In addition, CPR and LBR were not significantly associated with EMT increase.

CONCLUDES

EMT may increase, decrease or remain stable on the day of FET as compared with that of one day before progesterone administration. Whatever change in EMT that occurs after progesterone administration has no significant effect on CPR and LBR in FET cycles.

Impact of Gonadotropin-Releasing Hormone Agonist Pre-treatment on the Cumulative Live Birth Rate in Infertile Women With Adenomyosis Treated With IVF/ICSI: A Retrospective Cohort Study

Introduction: Although pre-treatment with a GnRH agonist can reduce the size of adenomyosis lesions, the supra-physiological hormone level induced by controlled ovarian hyperstimulation (COH) may negate the usefulness of the GnRH agonist in patients with adenomyosis lesions, leading to continued poor outcomes in fresh embryo transfer cycles during in vitro fertilization (IVF). It is unclear whether GnRH agonist pre-treatment before starting the long GnRH agonist protocol for IVF/ICSI (intracytoplasmic sperm injection) can improve cumulative live birth rate (CLBR) of infertile women with adenomyosis. Method: In this retrospective cohort study, a total of 374 patients diagnosed as adenomyosis (477 cycles) underwent IVF/ICSI with long GnRH agonist protocol with or without GnRH agonist pre-treatment between January 2009 and June 2018. Logistic regression was used to assess the association between GnRH agonist pre-treatment and pregnancy outcome after adjusting for confounding factors. Results: The live birth rate in fresh embryo transfer cycles was higher in the non-pre-treatment group than in the GnRH agonist pre-treatment group (37.7 vs. 21.2%, P = 0.028); the adjusted odds ratio (OR) for the long agonist protocol without pre-treatment was 1.966 (95% CI: 0.9-4.296, P = 0.09). The CLBR was higher in the non-pre-treatment group than in the GnRH agonist pre-treatment group (40.50 vs. 27.90%, P = 0.019); the adjusted OR for the long agonist protocol without pre-treatment was 1.361 (95% CI: 0.802-2.309, P = 0.254). Conclusion: Our results indicated that GnRH agonist pre-treatment before starting the long GnRH agonist protocol does not improve the live birth rate in fresh embryo transfer cycles or CLBR in infertile women with adenomyosis after IVF/ICSI treatment when compared to that in non-pre-treated patients. A subsequent prospective randomized controlled study is needed to confirm these results.

The impact of endometrial thickness change after progesterone administration on pregnancy outcome in patients transferred with single frozen-thawed blastocyst

BACKGROUND

The aim of this study was to explore the impact of endometrial thickness change after progesterone administration on pregnancy outcome in patients transferred with single frozen-thawed blastocyst.

METHODS

This observational cohort study included a total of 3091 patients undergoing their first frozen-thawed embryo transfer (FET) cycles between April 2015 to March 2019. Endometrial thickness was measured by trans-vaginal ultrasound twice for each patient: on day of progesterone administration, and on day of embryo transfer. The change of endometrial thickness was recorded.

RESULTS

Regardless of endometrial preparation protocol (estrogen-progesterone/natural cycle), female age, body mass index (BMI), and infertility diagnosis were comparable between patients with an increasing endometrium on day of embryo transfer and those without. However, clinical pregnancy rate increases with increasing ratio of endometrial thickness. Compared with patients with Non-increase endometrium, those with an increasing endometrium on day of embryo transfer resulted in significantly higher clinical pregnancy rate (56.21% vs 47.13%, P = 0.00 in estrogen-progesterone cycle; 55.15% vs 49.55%, P = 0.00 in natural cycle).

CONCLUSIONS

In most patients, endometrial thickness on day of embryo transfer (after progesterone administration) increased or kept being stable compared with that on day of progesterone administration. An increased endometrium after progesterone administration was associated with better pregnancy outcome.

Predictive factors for biochemical pregnancy in intracytoplasmic sperm injection cycles

The aim of this study was to investigate which factors contribute to the incidence of biochemical pregnancy (BP) in intracytoplasmic sperm injection (ICSI) cycles. This cohort study included cycles performed from June 2010 to September 2016 in a private, university-affiliated IVF centre. Cycles were split into four groups, depending on the pregnancy outcomes: Clinical Pregnancy (CP, n = 903), Biochemical Pregnancy (BP, n = 55), Miscarriage (MI, n = 142) and Negative Pregnancy (NP, n = 2034). The effects of ovarian stimulation, laboratory data and seminal parameters on pregnancy outcomes were evaluated using adjusted general linear models. Discriminant analyses were conducted to construct a model for pregnancy prediction and to establish cut-offs for BP. The total sperm count (p = 0.035), total and progressive sperm motility (p = 0.001 and p = 0.023, respectively), total motile sperm count (TMSC, p = 0.029) and the endometrial thickness (p < 0.001) were lower among BP group cycles. Lower rates of high-quality cleavage-stage embryos were observed in the BP group compared to CP and MI groups (p < 0.001). In discriminant analyses, cut-offs for BP prediction were established for the following factors: endometrial thickness < 11 mm, sperm motility < 55.5% and total dose of follicle-stimulating hormone (FSH)> 2400 IU. The incidence of biochemical pregnancy was four times higher when the aforementioned factors did not meet the defined cut-offs. The combination of suboptimal endometrial development and poor seminal and embryo quality contribute to an increased incidence of biochemical pregnancy in ICSI cycles.