Gonadotropin-releasing hormone agonist combined with hormone replacement therapy does not improve the reproductive outcomes of frozen-thawed embryo transfer cycle in elderly patients: a retrospective study

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.

Combination of bone marrow mesenchymal stem cells and moxibustion restores cyclophosphamide-induced premature ovarian insufficiency by improving mitochondrial function and regulating mitophagy

BACKGROUND

Premature ovarian insufficiency (POI) is a major cause of infertility. In this study, we aimed to investigate the effects of the combination of bone marrow mesenchymal stem cells (BMSCs) and moxibustion (BMSCs-MOX) on POI and evaluate the underlying mechanisms.

METHODS

A POI rat model was established by injecting different doses of cyclophosphamide (Cy). The modeling of POI and the effects of the treatments were assessed by evaluating estrous cycle, serum hormone levels, ovarian weight, ovarian index, and ovarian histopathological analysis. The effects of moxibustion on BMSCs migration were evaluated by tracking DiR-labeled BMSCs and analyzing the expression of chemokines stromal cell-derived factor 1 (Sdf1) and chemokine receptor type 4 (Cxcr4). Mitochondrial function and mitophagy were assessed by measuring the levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), ATP, and the mitophagy markers (Drp1, Pink1, and Parkin). Furthermore, the mitophagy inhibitor Mdivi-1 and the mitophagy activator CCCP were used to confirm the role of mitophagy in Cy-induced ovarian injury and the underlying mechanism of combination therapy.

RESULTS

A suitable rat model of POI was established using Cy injection. Compared to moxibustion or BMSCs transplantation alone, BMSCs-MOX showed improved outcomes, such as reduced estrous cycle disorders, improved ovarian weight and index, normalized serum hormone levels, increased ovarian reserve, and reduced follicle atresia. Moxibustion enhanced Sdf1 and Cxcr4 expression, promoting BMSCs migration. BMSCs-MOX reduced ROS levels; upregulated MMP and ATP levels in ovarian granulosa cells (GCs); and downregulated Drp1, Pink1, and Parkin expression in ovarian tissues. Mdivi-1 significantly mitigated mitochondrial dysfunction in ovarian GCs and improved ovarian function. CCCP inhibited the ability of BMSCs-MOX treatment to regulate mitophagy and ameliorate Cy-induced ovarian injury.

CONCLUSIONS

Moxibustion enhanced the migration and homing of BMSCs following transplantation and improves their ability to repair ovarian damage. The combination of BMSCs and moxibustion effectively reduced the excessive activation of mitophagy, which helped prevent mitochondrial damage, ultimately improving ovarian function. These findings provide a novel approach for the treatment of pathological ovarian aging and offer new insights into enhancing the efficacy of stem cell therapy for POI patients.

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.

Clinical Outcomes in Hormone Replacement Therapy (HRT)-Frozen Embryo Transfer (FET) Protocol Increased by Administering Gonadotropin-Releasing Hormone Agonist (GnRH) in the Initial Stage of the Luteal Phase: A Retrospective Analysis

OBJECTIVE

The objective of this study was to determine if gonadotropin-releasing hormone agonist (GnRH) administration supporting the luteal phase in frozen embryo transfer (FET) improves clinical outcomes Methods and materials This is a retrospective cohort study and we analyzed 3515 cycles of FET at the Department of Reproductive Medicine in our hospital from February 2018 through December 2021. Patients were divided into the GnRH (triptorelin+progesterone and human chorionic gonadotropin (hCG)) group and the non-GnRHa (existing treatment without triptorelin) group. There were 1033 and 2485 cases in the above groups, respectively. Live birth rates (LBR) and clinical pregnancy rates (CPR) were contrasted in the two groups.

RESULTS

We found greater CPR (58.00% versus 48.40%, P-value = 0.003) and LBR (52.70% versus 45.60%, P-value = 0.001) for HRT-FET cycles, and found no clinical significance for natural cycle FET (NC-FET) (58.20% versus 52.90%, P-value = 0.364 and 54.40% versus 47.00%, P-value=0.211), GnRH+HRT-FET (53.00% versus 53.00%, P-value=0.176 and 46.20% versus 47.30%, P-value=0.794), and stimulation-FET (59.30% versus 52.90%, P-value=.00.566 and 59.30% versus 47.10%, P-value=.00.247) in terms of CPR and LBR in the two groups. There was a 47% increase in CPR in the GnRH group, and there was a 33% increase in LBR in the same group.

CONCLUSION

During HRT-FET cycles, administering triptorelin three to four times in the existing luteal support can improve CPR and LBR, and administering triptorelin during the initial stage of the luteal phase can prove a new option for luteal support.

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.

Agonist long protocol improves outcomes of vitrified-warmed embryo transfer in repeatedly thin endometrium

RESEARCH QUESTION

Does follicular stimulation using human menopausal gonadotrophin (HMG) after pituitary down-regulation by a GnRH agonist improve endometrial thickness (EMT) and clinical outcomes of frozen-thawed embryo transfer (FET; using vitrified-warmed embryos) in women with thin endometrium after intensified oestrogen administration (IOA)?

DESIGN

This was a retrospective study. A total of 627 patients attempted 683 FET cycles with at least one previous history of thin endometrium. None of the cycles reached over 7 mm EMT after using oral and vaginal oestradiol for more than 21 days (IOA protocol). A total of 129 cycles proceeded with FET, 305 cycles were cancelled, and 249 cycles involved administration of HMG following GnRH agonist pituitary down-regulation (GnRH agonist + HMG protocol) for further endometrial preparation.

RESULTS

EMT became significantly greater (7.18 ± 1.14 mm versus 6.13 ± 0.63 mm, P < 0.001) using GnRH agonist + HMG compared with previous IOA cycles, but this was not related to serum oestrogen concentrations. A total of 213 cycles after the GnRH agonist + HMG protocol proceeded with FET, showing a significantly increased clinical pregnancy rate, implantation rate and live birth rate compared with those after IOA.

CONCLUSIONS

The GnRH agonist + HMG protocol for endometrial preparation in FET cycles improves EMT in women with a thin endometrium after IOA and showed significantly better clinical outcomes than IOA. The authors suggest that the GnRH agonist + HMG protocol should be used for EMT that is less than 7 mm after there has been no optimal response to IOA.

Gonadotropin-Releasing Hormone agonist (GnRH-a) Pretreatment before Hormone Replacement Therapy Does Not Improve Reproductive Outcomes of Frozen-Thawed Embryo Transfer Cycle in Older Patients with Intrauterine Fibroid: A Retrospective Cohort Study

BACKGROUND

Surgery in elder patients with intermural fibroids delays pregnancy, and GnRH-a can shrink uterine fibroids to a certain extent; therefore, for geriatric patients with fibroids, determining whether GnRH-a pretreatment before frozen-thawed embryo transfer (FET) can improve its success rate remains to be studied. We conducted this study to research whether GnRH-a pretreatment before hormone replacement treatment (HRT) could optimize the reproductive outcomes compared with others preparations in geriatric patients with intramural fibroids.

METHODS

According to the endometrial preparation, patients were divided into a GnRH-a-HRT group, a HRT group and a natural cycle (NC) group. The live birth rate (LBR) was the first outcome, and the clinical pregnancy outcome (CPR), the miscarriage rate, the first trimester abortion rate and the ectopic pregnancy rate were the secondary outcomes.

RESULTS

A total of 769 patients (aged 35 years or older) were included in this study. No significant difference was observed in the live birth rate (25.3% vs. 17.4% vs. 23.5%, p = 0.200) and the clinical pregnancy rate (46.3% vs. 46.1% vs. 55.4%, p = 0.052) among the three endometrial preparation regimens.

CONCLUSION

In this study, for the geriatric patient with the intramural myoma, the pretreatment with GnRH-a did not show any advantage over the NC and HRT preparation groups before the FET, and the LBR was not significantly increased.

Administration of depot GnRH agonist prior to programmed frozen-thawed embryo transfer does not improve the live birth rate in ovulatory women: A large, multi-center retrospective study

Despite that gonadotropin-releasing hormone (GnRH) agonist pretreatment has been widely used before programmed frozen-thawed transfer (FET), its impact on live birth rates in ovulatory women remains uncertain. In the present study, we aim to determine if GnRH agonists pretreatment before FET improves live birth rates in women undergoing in vitro fertilization with FET. Programmed FET cycles conducted in four infertility centers were retrospectively collected and reviewed for eligibility from January 2016 and December 2017. Patient's demographics, ovarian stimulation parameters, and pregnancy outcomes were compared between those given GnRH agonist pretreatment versus no pretreatment in ovulatory women undergoing FET cycles. A total of 6397 programmed cycles were screened for eligibility, of which 5049 cycles were included in the study for analysis. Compared with the group of no GnRH agonist pretreatment (n = 4143), women in the GnRH agonist group (n = 906) were older (33.0 vs 34.0, P < .001), had a higher proportion of subjects with previous transfer attempts and had a higher number of embryos transferred. After controlling for confounders, the logistic regression results showed that GnRH agonist pretreatment did not increase the odds of both clinical pregnancy (OR 0.92, 95% CI [0.70-1.20]), ongoing pregnancy (OR 0.91, 95% CI [0.69-1.19]) and live birth rates (OR 0.84, 95% CI [0.64-1.10]). However, when restricted to women who had no previous transfer attempts, women in the GnRH pretreatment group had lower odds of achieving live birth (OR 0.49, 95% CI [0.30-0.79]). Sensitivity analysis performed in patients with male factor infertility causes showed GnRH agonist pretreated group had lower live birth rates compared to no GnRH agonist pretreatment group (OR = 0.65, 95% CI [0.43-0.97]). Our findings suggested that GnRH agonist pretreatment does not bring additional benefits in live birth rate improvements for ovulatory women undergoing FET cycles. Therefore, the pros of using GnRH agonist to reduce premature ovulation should be weighed against the cons of prolonged time to pregnancy, discomforts resulting from pituitary suppression, and increased medical costs associated with GnRH agonist use.

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.

Gonadotropin-releasing hormone agonist downregulation combined with hormone replacement therapy improves the reproductive outcome in frozen-thawed embryo transfer cycles for patients of advanced reproductive age with idiopathic recurrent implantation failure

BACKGROUND

To determine whether gonadotropin-releasing hormone (GnRH) agonist downregulation combined with hormone replacement therapy (HRT) can improve the reproductive outcomes in frozen-thawed embryo transfer cycles for older patients (aged 36-43 years) with idiopathic recurrent implantation failure (RIF).

METHODS

This retrospective cohort study involved 549 older patients undergoing their third cleavage-stage embryo or blastocyst transfer over a 5-year period (January 2015-December 2020) at Northwest Women's and Children's Hospital after in vitro fertilization/intracytoplasmic sperm injection cycles. Patients with known endometriosis or adenomyosis were excluded from the study. The patients were divided into three groups according to the endometrial preparation protocol: the natural cycle (NC) group (n = 65), the HRT group (n = 194), and the GnRH agonist downregulation combined with HRT cycle (GnRH agonist-HRT) group (n = 290). The primary outcome was the live birth rate, and the secondary outcomes were the clinical pregnancy, miscarriage, and ongoing pregnancy rates.

RESULTS

The live birth rate in the GnRH agonist-HRT group (36.55%) was higher than that in the HRT group (22.16%) and NC group (16.92%) (P < 0.0001). Similarly, a logistic regression model adjusting for potential confounders showed that the live birth rate was higher in the GnRH agonist-HRT group than in the HRT group (odds ratio, 0.594; 95% confidence interval, 0.381-0.926; P = 0.021) and NC group (odds ratio, 0.380; 95% confidence interval, 0.181-0.796; P = 0.010).

CONCLUSIONS

The GnRH agonist-HRT protocol improves the live birth rate in frozen-thawed embryo transfer cycles for patients of advanced reproductive age with RIF. We hypothesize that the GnRH agonist-HRT protocol enhances implantation-related factors and promotes optimal endometrial receptivity, leading to an improved live birth rate. These findings are also useful for further investigating the underlying mechanism of the GnRH agonist-HRT protocol in improving the reproductive outcomes for patients of advanced reproductive age with RIF.

TRIAL REGISTRATION

This research protocol was approved by the hospital institutional ethics committee (No. 2021002).

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.

Effectiveness comparison between Endometrial Receptivity Array, Immune Profiling and the combination in treating patients with multiple implantation failure

PROBLEM

The clinical value of endometrial receptivity array (ERA), endometrial immune profiling, or a combination of both for multiple implantation failure patients is unclear.

METHOD OF STUDY

One hundred and seventy-two women with a history of at least two or more consecutive implantation failures in IVF/ICSI treatment were included. According to patients' willingness, they were divided into four groups, 'no treatment', 'Immune Profiling', 'ERA' and 'ERA + Immune Profiling'. Endometrial biopsy was examined by ERA, immune profiling alone, or combination, and intention was adopted accordingly. Pregnancy outcomes were compared, and the association between ERA phases and endometrial immune profiling was also assessed.

RESULTS

The overall incidence rate of the displaced window of implantation (WOI) and endometrial immune dysregulations were 84.9% and 75.3%, respectively. Implantation rate was significantly higher in the 'ERA + Immune Profiling' group than the 'no treatment' group (P = 0.007). Clinical pregnancy rate was somewhat improved in the three treatment groups but with a borderline significance (P = 0.071). After controlling for other confounders, 'ERA + Immune Profiling' treatment was associated with a higher pregnancy rate [aOR (95%CI)  =  3.412 (1.387-8.395), P = 0.008]. There was no association between endometrial immune profiling and ERA phases.

CONCLUSIONS

Our findings highlight the high incidence of displaced WOI and endometrial immune dysregulation in multiple implantation failure patients. The combination of ERA and endometrial immune profiling is more likely to have clinical value than ERA or immune profiling alone. These data suggested the unsubstitutability of ERA and endometrial immune profiling on the treatment outcome for multiple implantation failure patients. This article is protected by copyright. All rights reserved.

Association between endogenous LH level prior to progesterone administration and live birth rate in artificial frozen-thawed blastocyst transfer cycles of ovulatory women

STUDY QUESTION

Is there an association between serum LH levels prior to progesterone administration and live birth rate (LBR) in artificial frozen-thawed embryo transfer (FET) cycles?

SUMMARY ANSWER

: Low serum LH levels on the day before progesterone initiation in artificial frozen-thawed blastocyst transfer cycles of ovulatory women are associated with a lower LBR.

WHAT IS KNOWN ALREADY

In artificial FET cycles, exogenous oestrogen and progesterone are administered sequentially to mimic the serum hormone pattern similar to the natural cycle. In oestrogen-only phase, the supplemental oestrogen causes thickening of the endometrium and is sometimes accompanied by a rise in serum LH. However, whether the endogenous LH level in artificial FET cycles is related to clinical outcomes remains unclear.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study including 3469 artificial frozen-thawed blastocyst transfer cycles was conducted at a tertiary-care academic medical centre between February 2014 and January 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 3469 frozen blastocyst transfer cycles were stratified into four groups based on the quartiles of serum LH level before progesterone initiation: <25th percentile (LH < 8.79 mIU/ml), 25-50th percentile (8.79 ≤ LH ≤ 13.91 mIU/ml), 51-75th percentile (13.91 < LH ≤ 20.75 mIU/ml) and >75th percentile (LH > 20.75 mIU/ml). The serum LH level >75th percentile group was considered as the reference group. Patients with polycystic ovarian syndrome or other ovulatory disorders were excluded from the study. We also excluded cycles with an endometrial thickness <7 mm before progesterone initiation and patients with intrauterine adhesions and uterine abnormalities. In order to avoid the interference of BMI, all patients were divided into two categories based on the overweight threshold: BMI <25 kg/m2 and ≥25 kg/m2, and the impacts of serum LH levels on LBR were investigated separately. Univariable and multivariable logistic regression analysis were performed to adjust for potential confounders. EmpowerStats software and R-project were used to build smooth curve fitting models.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with the reference group, the implantation rate significantly decreased with low LH levels (<25th percentile) on the day before progesterone initiation (odds ratio [OR] = 0.74; 95% CI, 0.64-0.86; P = 0.001). Accounting for major covariates, low LH levels were associated with a relatively lower LBR (adjusted OR = 0.649; 95% CI, 0.531-0.794; P < 0.001), mainly due to a lower implantation rate, lower clinical pregnancy rate and higher pregnancy loss rate. Moreover, in the patients with BMI <25 kg/m2, low LH was associated with a lower LBR (P < 0.001); while in the overweight subgroup, LBR and LH were not correlated (P = 0.823).

LIMITATIONS, REASONS FOR CAUTION

The main limitation of this study is its retrospective design. Owing to the relatively small number in the overweight group, the results of the overweight subgroup should be interpreted with caution.

WIDER IMPLICATIONS OF THE FINDINGS

The evidence provided in this study shows the importance of serum LH levels on the day before progesterone initiation in patients undergoing artificial FET cycles. Hypothalamic dysfunction may be one of the important causes of a relatively low LH, which is related to impaired pregnancy outcomes. Serum LH levels may be used as one of the clinical indicators to predict pregnancy outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

No funding and no competing interest were involved in this study.

TRIAL REGISTRATION NUMBER

NA.

Live birth rates after natural cycle versus hormone replacement therapy for single euploid blastocyst transfers: a retrospective cohort study

RESEARCH QUESTION

Is there any difference in live birth rate between the natural cycle and hormone replacement therapy (HRT) endometrial preparation protocols for women with regular menstrual cycles undergoing their first single vitrified-warmed euploid blastocyst transfer?

DESIGN

This was a retrospective cohort study that enrolled 722 women who underwent vitrified-warmed euploid blastocyst transfer at assisted reproductive technology (ART) centre of The First Affiliated Hospital of Zhengzhou University, from January 2013 to December 2019. Univariate and multivariate logistic regression models were used to analyse the relationship between the endometrial preparation protocols and live birth rates. Stratified analyses and sensitivity analyses were performed to ensure the reliability and stability of the results.

RESULTS

A total of 722 single vitrified-warmed euploid blastocyst transfer cycles were included. Overall, the live birth rates were 50.00% (110/220) in the natural cycle group and 47.61% (239/502) in the HRT group. Multiple logistic regression analyses showed that there was no significant association (adjusted odds ratio 0.82; 95% confidence interval 0.56-1.20; P = 0.313) between natural cycle and HRT protocols and the live birth rate. Interaction analysis showed that there was no significant difference in live birth rates between the two groups for any subgroup after adjusting for confounding factors.

CONCLUSIONS

For single vitrified-warmed euploid blastocyst transfer, natural cycle and HRT endometrial preparation protocols result in similar live birth rates among women with regular menstrual cycles. Further studies are needed into the effects of endometrial preparation protocols on pregnancy outcomes.