Endometrial Preparation for Frozen-Thawed Embryo Transfer With or Without Pretreatment With GnRH Agonist: A Randomized Controlled Trial at Two Centers

Endometrial preparation protocols did not impact pregnancy outcomes of patients with cured chronic endometritis

RESEARCH QUESTION

Do endometrial preparation protocols have an effect on pregnancy outcomes in patients with cured chronic endometritis?

DESIGN

A retrospective study was conducted on 3721 infertile patients from December 2018 to August 2020. Endometrial tissues obtained during the proliferative phase were immunostained for CD138. The presence of CD138-positive cells within the stromal cells indicated chronic endometritis. All patients diagnosed with chronic endometritis received oral antibiotics. Patients underwent endometrial preparation and frozen embryo transfer once chronic endometritis was cured. This study compared various endometrial preparation protocols to assess their effects on pregnancy outcomes. Additionally, it aimed to investigate differences in pregnancy outcomes between patients without chronic endometritis and patients with cured chronic endometritis while following the same endometrial preparation protocol.

RESULTS

Almost no differences in pregnancy outcomes were observed between natural cycle, hormone replacement therapy (HRT) and gonadotrophin-releasing hormone agonist-HRT (GnRH agonist-HRT) protocols in patients without chronic endometritis and patients with cured chronic endometritis. The only notable difference was that, among women without chronic endometritis, the early miscarriage rate was higher for the GnRH agonist-HRT protocol (25.8%) compared with the natural cycle (17.4%) and HRT (17.7%) protocols (P = 0.025). However, this difference was not significant after adjusting for confounders (adjusted OR 1.383, 95% CI 0.931-2.055). The live birth rate, clinical pregnancy rate, early miscarriage rate, ectopic pregnancy rate and ongoing pregnancy rate did not differ significantly (P > 0.05) between patients without chronic endometritis and patients with cured chronic endometritis who underwent natural cycle, HRT and GnRH agonist-HRT protocols.

CONCLUSION

Endometrial preparation protocols had no impact on pregnancy outcomes in patients with cured chronic endometritis.

Effect of GnRH agonist down-regulation combined with hormone replacement treatment on reproductive outcomes of frozen blastocyst transfer cycles in women of different ages

Objective

To investigate the effect of GnRH agonist (GnRH-a) down-regulation prior to hormone replacement treatment (HRT) to prepare the endometrium in frozen embryo transfer (FET) cycles in women of different ages.

Methods

This was a retrospective study, and after excluding patients with adenomyosis, endometriosis, severe endometrial adhesions, polycystic ovary syndrome (PCOS), and repeated embryo implantation failures, a total of 4,091 HRT cycles were collected. Patients were divided into group A (<35 years old) and group B (≥35 years old), and each group was further divided into HRT and GnRHa-HRT groups. The clinical outcomes were compared between groups.

Results

There was no statistically significant difference in clinical outcomes between the HRT and GnRHa-HRT groups among women aged <35 years. In women of advanced age, higher rates of clinical pregnancy and live birth were seen in the GnRHa-HRT group. Logistic regression analysis showed that female age and number of embryos transferred influenced the live birth rate in FET cycles, and in women aged ≥ 35 years, the use of GnRH-a down-regulation prior to HRT improved pregnancy outcomes.

Conclusions

In elderly woman without adenomyosis, endometriosis, PCOS, severe uterine adhesions, and RIF, hormone replacement treatment with GnRH agonist for pituitary suppression can improve the live birth rate of FET cycles.

Pituitary Suppression with Gonadotropin-Releasing Hormone Agonist Prior to Artificial Endometrial Preparation in Frozen-Thawed Embryo Transfer Cycles: A Systematic Review and Meta-Analysis of Different Protocols and Infertile Populations

This study investigates the effect of GnRHa pretreatment on pregnancy outcomes in artificial endometrial preparation for frozen-thawed embryo transfer (AC-FET) cycles. A systematic review of English language studies published before 1 September 2022, was conducted, excluding conference papers and preprints. Forty-one studies involving 43,021 participants were analyzed using meta-analysis, with a sensitivity analysis ensuring result robustness. The study found that GnRHa pretreatment generally improved the clinical pregnancy rate (CPR), implantation rate (IR), and live birth rate (LBR). However, discrepancies existed between randomized controlled trials (RCTs) and observational studies; RCTs showed no significant differences in outcomes for GnRHa-treated cycles. Depot GnRHa protocols outperformed daily regimens in LBR. Extended GnRHa pretreatment (two to five cycles) significantly improved CPR and IR compared to shorter treatment. Women with polycystic ovary syndrome (PCOS) saw substantial benefits from GnRHa pretreatment, including improved CPR and LBR and reduced miscarriage rates. In contrast, no significant benefits were observed in women with regular menstruation. More rigorous research is needed to solidify these findings.

Pretreatment with a long-acting GnRH agonist for frozen-thawed embryo transfer cycles: how to improve live birth?

BACKGROUND

Whether pretreatment with gonadotropin-releasing hormone agonist (GnRHa) can improve the pregnancy outcomes in frozen-thawed embryo transfer (FET) cycles is controversial. The inconsistencies in the results of different studies would be related to the characteristics of the included patients and the protocol of GnRHa use. In this study, we investigated the efficacy of pretreatment with a long-acting GnRH agonist in the early follicular phase of FET cycles and determined which population was suitable for the protocol.

RESULTS

We retrospectively included 630 and 1141 patients in the GnRHa FET and hormone replacement treatment (HRT) FET without GnRHa groups respectively, between October 2017 and March 2019 at a university-affiliated in vitro fertilization center. On the second or third day of menstruation, 3.75 mg of leuprorelin was administered. After 14 days, HRT was initiated for endometrial preparation. No significant differences were observed between the two groups in terms of patient characteristics. However, the GnRHa FET group showed a higher percentage of endometrium with a triple line pattern (94.8% vs 89.6%, p < 0.001) on the day of progesterone administration, with increased implantation (35.6% vs 29.8%, p = 0.005), clinical pregnancy (49.8% vs 43.3%, p = 0.008), and live birth rate (39.4% vs 33.7%, p = 0.016), than the HRT FET cycles with similar endometrial thickness, ectopic pregnancy and early miscarriage rates. Binary logistic regression analysis showed the GnRHa FET group to be associated with an increased chance of clinical pregnancy (P=0.028, odds ratio [OR] 1.32, 95% confidence interval [CI] 1.03-1.70) and live birth (P=0.013, odds ratio [OR] 1.34, 95% confidence interval [CI] 1.06-1.70) compared to the HRT FET without GnRHa group. After subgroup analysis, we found that the GnRHa FET group showed a significantly higher live birth rate in the subgroups of age < 40 years, primary infertility, with polycystic ovary syndrome (PCOS), and irregular menstruation.

CONCLUSIONS

Pretreatment with a long-acting GnRHa during the early follicular phase improved the live birth rate in FET cycles. Age < 40 years, primary infertility, PCOS, and irregular menstruation are effective indications for endometrial preparation with GnRHa pretreatment in FET cycles. However, further randomized controlled trials are required to verify these results.

Retrospective analysis of the endometrial preparation protocols for frozen-thawed embryo transfer cycles in women with endometriosis

BACKGROUND

There was inconsistency in optimal endometrial preparation protocol for frozen-thawed embryo transfer (FET) in patients with endometriosis. We conducted this study to investigate the effect of different endometrial preparation protocols on the pregnancy outcomes in patients with endometriosis undergoing FET cycles, and determine the optimal number of GnRHa injections in GnRHa-HRT protocols.

METHOD(S)

This was a retrospective cohort analysis of women with endometriosis who underwent FET cycles at a single university-based center. This study retrospectively analyzed 2048 FET cycles in our center from 2011 to 2020. According to the endometrial preparation protocols, patients were divided into 4 groups: gonadotropin releasing hormone agonist-hormone replacement therapy(GnRHa-HRT), hormone replacement therapy(HRT), ovulation induction(OI), and natural cycle(NC). In the GnRHa-HRT group, patients were further divided into 3 groups: one injection of GnRHa, two injections of GnRHa, and three or more injections of GnRHa. The primary outcome was the clinical pregnancy rate. Propensity score matching was used to adjust for potential non-similarities among the groups. Multivariate logistic regression analysis was performed to figure out the risk factors for pregnancy outcomes.

RESULT(S)

There were no statistical differences in pregnancy outcomes among the four endometrial preparation protocols in FET cycles with endometriosis patients, the results retained after propensity score matching(PSM). And in endometriosis patients complicated with adenomyosis, the results remained similar. In patients with GnRHa-HRT protocol, there were no differences in clinical pregnancy rate and live birth rate with different numbers of GnRHa injections, the early miscarriage rate were 18% in the two injections of GnRHa group and 6.5% in the one injection of GnRHa group(P = 0.017). Multifactorial logistic regression analysis showed that two injections of GnRHa before FET was associated with increased early miscarriage rate compared with one injection of GnRHa[adjusted OR (95% CI): 3.116(1.079-8.998),p = 0.036].

CONCLUSION(S)

The four kinds of endometrial preparation protocols for FET, GnRHa-HRT, HRT, OI and NC had similar pregnancy outcomes in patients with endometriosis. In endometriosis patients complicated with adenomyosis, the results remained similar. In patients with endometriosis undergoing GnRHa-HRT protocol for FET, more injections of GnRHa had no more advantages in pregnancy outcomes, on the contrary, it might increase the early miscarriage rate.

Young women were associated with higher risk of hypertensive disorders of pregnancy and cesarean section from hormone replaced cycles in frozen-thawed embryo transfer: a retrospective study of 5316 singleton deliveries

Background

The utilization of frozen-thawed embryo transfer (FET) cycles has been linked to heightened risks of adverse perinatal outcomes. However, the potential association between adverse perinatal outcomes and distinct endometrial preparation regimens remains unclear. Therefore, we aim to investigate the maternal and neonatal outcomes after hormone replacement treatment (HRT) cycles, natural cycles (NC) and HRT cycles with pretreatment using GnRHa (HRT + GnRHa) for ovulatory women undergoing FET cycles.

Methods

A large sample retrospective cohort study was carried out from 2016 to 2020. The data included a total of 5316 women who had singleton deliveries undergoing FET cycles and which were divided into three groups based on different endometrial preparation protocols: 4399 patients in HRT groups, 621 in GnRHa+HRT groups, 296 in NC groups. The outcomes consisted of maternal outcomes (cesarean section, hypertensive disorders of pregnancy (HDP), placenta previa, gestational diabetes mellitus (GDM));and neonatal outcomes (preterm birth, newborn birthweight, low birthweight, small for gestational age (SGA), macrosomia, large for gestational age (LGA), fetal malformation).

Results

After adjusting for a series of confounding variables, we found an increased risk of HDP (aOR=3.362; 95%CI, 1.059-10.675) and cesarean section (aOR=1.838; 95%CI, 1.333-2.535) in HRT cycles compared with NC, especially for ovulatory women under 35 years old. However, in all three groups, newborn birth weight was not significantly different. Meanwhile, perinatal outcomes did not differ significantly in terms of perinatal outcomes in HRT +GnRHa cycles compared with HRT cycles solely.

Conclusion

During FET cycles, singletons from HRT were related to higher risks of HDP and cesarean section, particularly for young women. GnRHa pretreatment didn't bring any benefit to perinatal outcomes compared with HRT cycles alone. Therefore, the natural cycle may be a more appropriate and safer option for young ovulatory women.

Preparation of the endometrium for frozen embryo transfer: an update on clinical practices

Over the past decade, the application of frozen-thawed embryo transfer treatment cycles has increased substantially. Hormone replacement therapy and the natural cycle are two popular methods for preparing the endometrium. Hormone replacement therapy is now used at the discretion of the doctors because it is easy to coordinate the timing of embryo thawing and transfer with the schedules of the in-vitro fertilization lab, the treating doctors, and the patient. However, current results suggest that establishing a pregnancy in the absence of a corpus luteum as a result of anovulation may pose significant maternal and fetal risks. Therefore, a 'back to nature' approach that advocates an expanded use of natural cycle FET in ovulatory women has been suggested. Currently, there is increasing interest in how the method of endometrial preparation may influence frozen embryo transfer outcomes specifically, especially when it comes to details such as different types of ovulation monitoring and different luteal support in natural cycles, and the ideal exogenous hormone administration route as well as the endocrine monitoring in hormone replacement cycles. In addition to improving implantation rates and ensuring the safety of the fetus, addressing these points will allow for individualized endometrial preparation, also as few cycles as possible would be canceled.

Additional single dose GnRH agonist during luteal phase support may improve live birth rate in GnRHa-HRT frozen-thawed embryo transfer cycle: a retrospective cohort study

BACKGROUND

GnRH agonist (GnRHa) has been reported to have direct effects and functional roles in the endometrium and embryos. Several meta-analyses have shown that GnRHa administration in the luteal phase improved the live birth rate or pregnancy rate in both fresh and frozen embryo transfer (FET) cycles. The aim of this study was to investigate whether luteal GnRHa administration could also improve in vitro fertilization (IVF) outcomes in patients undergoing hormone replacement therapy (HRT) cycles with GnRHa suppression.

METHODS

The retrospective cohort study included a total of 350 patients undergoing GnRHa-HRT FET cycles. The study group included 179 patients receiving an additional single dose of GnRHa in the luteal phase following embryo transfer. A total of 171 patients in the control group did not receive luteal GnRHa. The baseline and cycle characteristics and reproductive outcomes were compared between the two groups.

RESULTS

Baseline and cycle characteristics were similar between the two groups, except lower AMH levels were found in the luteal GnRHa group than in the control group. The luteal GnRHa group had a significantly higher ongoing pregnancy rate and live birth rate than the control group. The multivariate analysis revealed that luteal GnRHa administration was positively associated with ongoing pregnancy (OR 2.04, 95% CI 1.20-3.47, P = 0.008) and live birth (OR 2.03, 95% CI 1.20-3.45, P = 0.009). When the subgroup of patients with recurrent implantation failure was analyzed, the multivariate analysis also showed that luteal GnRHa administration had beneficial effects on ongoing pregnancy (OR 4.55, 95% CI 1.69-12.30, P = 0.003) and live birth (OR 4.30, 95% CI 1.59-11.65, P = 0.004).

CONCLUSIONS

Our data suggest that the addition of one luteal dose of GnRHa may improve the live birth rate in patients undergoing the GnRHa-HRT protocol.

Which endometrial preparation protocol provides better pregnancy and perinatal outcomes for endometriosis patients in frozen-thawed embryo transfer cycles? A retrospective study on 1413 patients

OBJECTIVE

To determine the optimal endometrial preparation protocol for a frozen embryo transfer in patients with endometriosis.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care academic medical center.

PATIENT(S)

One thousand four hundred thirteen patients with endometriosis who underwent oocyte aspiration from 2015 to 2020 and frozen embryo transfer from 2016 to 2020 and received natural cycle, hormone replacement treatment with or without GnRHa pretreatment endometrial preparation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate, live birth rate, miscarriage rate, multiple pregnancy rate, biochemical pregnancy rate and ectopic pregnancy rate. Singleton live births were assessed for perinatal outcomes and obstetric complications.

RESULT(S)

There were no differences in clinical pregnancy outcomes or prenatal outcomes among the three commonly used endometrial preparation protocols for frozen embryo transfer cycles in patients with endometriosis. Results remained after screening variables using univariate logistic regression into multivariate logistic regression. No advantages or disadvantages were found among the three endometrial preparation protocols in patients with endometriosis.

CONCLUSION(S)

Natural cycle, hormone replacement cycle, or hormone replacement treatment with GnRHa pretreatment showed no superiority or inferiority in pregnancy and perinatal outcomes in patients with endometriosis.

STROBE-GnRHa pretreatment in frozen-embryo transfer cycles improves clinical outcomes for patients with persistent thin endometrium: A case-control study

The well-prepared endometrium with appropriate thickness plays a critical role in successful embryo implantation. The thin endometrium is the main factor of frozen-embryo transfer (FET), resulting in the failure of implantation undergoing FET. Hormone treatment is suggested to improve endometrium thickness; however, among the larger numbers of cases, it cannot reach the sufficient thickness, which leads to a high cancelation rate of embryo transfer as well as waste high-quality embryos. Thus, it increases the burden to patients in both economic and psychological perspectives. We performed a retrospective observational study, which was composed with 2 cohorts, either with the conventional hormone replacement therapy (HRT) protocol or HRT with gonadotrophin-releasing hormone agonist (GnRHa) pretreatment to prepare the endometrium before FET. The measurements of endometrium thickness, hormone level, transfer cycle cancelation rate, pregnancy rate, and implantation rate were retrieved from the medical records during the routine clinic visits until 1 month after embryo transfer. The comparisons between 2 cohorts were performed by t-test or Mann-Whitney U test depending on the different attributions of data. In total, 49 cycles were under HRT with GnRHa pretreatment and 84 cycles were under the conventional HRT protocol. HRT with GnRHa pretreatment group improved the endometrial thickness (8.13 ± 1.79 vs 7.51 ± 1.45, P = .031), decreased the transfer cancelation rate (P = .003), and increased clinical pregnancy rate and implantation rate significantly (both P = .001). Additionally, luteinizing hormone level in pretreatment group was consistently lower than conventional HRT group (P < .05). Our study revealed HRT with GnRHa pretreatment efficiently improved the endometrial thickness, therefore, decreased the FET cycle cancelation. It also elevated the embryo implantation rate and clinical pregnancy rate by improving endometrial receptivity.

Effect of artificial cycle with or without GnRH-a pretreatment on pregnancy and neonatal outcomes in women with PCOS after frozen embryo transfer: a propensity score matching study

BACKGROUND

In frozen embryo transfer (FET), there is limited consensus on the best means of endometrial preparation in terms of the reproductive outcomes in women with polycystic ovary syndrome (PCOS). The present study aimed to compare the pregnancy and neonatal outcomes following artificial cycle FET (AC-FET) with or without gonadotropin-releasing hormone agonist (GnRH-a) pretreatment among women with PCOS.

METHODS

A total of 4503 FET cycles that satisfied the inclusion criteria were enrolled in this retrospective cohort study between 2015 and 2020. The GnRH-a group received GnRH-a pretreatment while the AC-FET group did not. Propensity score matching (PSM) method and multivariate logistic regression analysis were performed to adjust for potential confounding factors.

RESULTS

After PSM, women in the GnRH-a group suffered a significantly lower miscarriage rate (11.2% vs. 17.1%, P = 0.033) and a higher live birth rate (LBR) compared with those in the AC-FET group (63.1% vs. 56.8%, P = 0.043). No differences were observed in the rates of biochemical pregnancy, clinical pregnancy and ectopic pregnancy between the two groups. A higher mean gestational age at birth was observed in the GnRH-a group than in the AC-FET group (39.80 ± 2.01 vs. 38.17 ± 2.13, P = 0.009). The incidence of neonatal preterm birth (PTB) in the GnRH-a group was lower than that in the AC-FET group (7.4% vs. 14.9%, P = 0.009). Singleton newborns conceived after GnRH-a group were more likely to be small for gestational age (SGA) than those born after AC-FET group (16.4% vs. 6.8%, P = 0.009). However, no significant differences were found between the two groups in terms of mean birthweight, apgar score, the rates of macrosomia, large for gestational age and low birth weight.

CONCLUSION(S)

In women with PCOS who underwent AC-FET, GnRH-a pretreatment was significantly associated with a higher live birth rate and a reduced risk of neonatal PTB. However, there was a concomitant increase in the risk of developing SGA babies.

HCG Trigger of GnRH Agonist-Induced Functional Ovarian Cysts Does Not Decrease Clinical Pregnancy Rate in GnRHa Pretreated Frozen Cycles: Evidence From a Retrospective Cohort Study

BACKGROUND

GnRH agonist (GnRHa) pretreatment before the frozen-thawed embryo transfer (FET) was increasingly utilized. However, the incidence of GnRHa-induced functional ovarian cysts (FC) was inevitable. The feasibility and efficacy of HCG triggering GnRHa-induced FC are unknown.

OBJECTIVE

The aim of the study was to investigate the effect of HCG triggering GnRHa-induced FC on FET outcomes.

METHODS

A total of 657 HRT-FET cycles with GnRHa pretreatment were retrospectively analyzed. Patients were divided into the FC group and the no functional cysts (NC) group according to whether the patient developed FC (follicular diameter of ≥7 mm and E₂ of ≥100 pg/ml). Risk factors associated with the incidence of GnRHa-induced FC were determined by multivariate regression analysis. Pregnancy outcomes were compared between the FC group and the NC group. Propensity score matching (PSM) was performed to reduce the impact of confounding factors. Three multivariate regression models were performed to assess the association between HCG triggering GnRHa-induced FC and clinical pregnancy. Interactive analysis and subgroup analysis were also analyzed.

RESULTS

The incidence rate of GnRHa-induced FC was 9.74%. Older age (aOR 1.10, 95% CI 1.05-1.15, p-value < 0.001) and lower BMI (aOR 0.81, 95% CI 0.71-0.93, p-value=0.002) are risk factors for GnRHa-induced FC. The implantation rate, clinical pregnancy rate (CPR), and miscarriage rate were not significantly different between the FC group and the NC group before or after PSM (p-value > 0.05). Multivariate logistic models showed that HCG triggering GnRHa-induced FC does not decrease CPR in the general population (p-value > 0.05). The effect of HCG triggering GnRHa-induced FC on clinical pregnancy is interactive with age (p-value for interaction: 0.003); HCG trigger is associated with significantly higher CPR than HRT-FET cycles without FC in patients ≥35 years (aOR 4.40, 95% CI 1.57-12.3, p-value = 0.005).

CONCLUSIONS

HCG triggering GnRHa-induced FC does not decrease the chance of clinical pregnancy in HRT-FET cycles pretreated with GnRHa.