Letrozole as co-treatment agent in ovarian stimulation antagonist protocol in poor responders: A double-blind randomized clinical trial

The Efficacy of Letrozole Co-Treatment in an Antagonist Protocol for Women with Polycystic Ovary Syndrome Undergoing IVF: A Retrospective Study

Objective

Our objective was to investigate the efficacy of letrozole co-treatment in an antagonist protocol for infertile women with polycystic ovary syndrome (PCOS).

Patients and Methods

This retrospective cohort study included infertile women with PCOS undergoing IVF/ICSI with and without letrozole co-treatment in an antagonist protocol from 2007-2021 at Shanghai Ninth People's Hospital (Shanghai, China). A total of 1559 participants were enrolled, with 1227 women in the antagonist group and 332 women in the letrozole co-treatment group. Propensity score-based patient-matching model was conducted to balance covariates between the groups. The primary outcome was the number of retrieved oocytes, with secondary outcomes including endocrine parameters, ovarian stimulation outcomes, pregnancy outcomes, and obstetrical and neonatal complications.

Results

Letrozole co-treatment induced significant changes in hormonal regulation, increased the percentage of large follicles, and resulted in fewer retrieved oocytes (P < 0.05). However, there was no negative impact on the number of usable embryos or good-quality embryos (P > 0.05). The live birth rates following fresh embryo transfer were comparable between the letrozole and control groups (single embryo transfer: 28.9% vs 29.7%, P > 0.05; double embryo transfer: 37.3% vs 45.6%, P > 0.05). Additionally, there were no significant differences between the two groups in the live birth rate per patient after frozen embryo transfer and the cumulative live birth rate (P > 0.05). No significant differences in obstetrical and neonatal complications were observed between the groups (P > 0.05).

Conclusion

The addition of letrozole to the antagonist protocol for women with PCOS undergoing IVF induces a higher percentage of large follicles during oocyte retrieval, while reducing the overall number of retrieved oocytes. Moreover, the use of letrozole demonstrates comparable clinical outcomes following embryo transfers. These findings highlight the potential application of letrozole in an antagonist protocol for women with PCOS.

Impact of 2.5 mg versus 5 mg letrozole co-treatment in an antagonist protocol for IVF: a retrospective study

Objective

The present study aimed to compare the effectiveness of two different doses of letrozole (2.5 mg and 5 mg daily) in an antagonist protocol for infertile women with normal ovarian reserve.

Methods

This retrospective cohort study included infertile women who underwent in vitro fertilization treatment with letrozole co-treatment at doses of 2.5 mg and 5 mg from 2007 - 2021 at Shanghai Ninth People's Hospital (Shanghai, China). The control group comprised infertile women who received gonadotropin-releasing hormone antagonist alone. The primary outcome was the cumulative live birth rate, while secondary outcomes included follicular phase endocrine parameters, ovarian stimulation outcomes, pregnancy outcomes, and the incidences of maternal and neonatal complications. Baseline and follow-up data were compared between the groups using ANOVA for normally distributed variables, the Kruskal-Wallis test for non-normally distributed variables, and the Chi-square test for categorical variables.

Results

A total of 422 participants were enrolled in the study, with 211 women in the antagonist group, 109 women in the 2.5 mg letrozole co-treatment group, and 102 women in the 5 mg letrozole co-treatment group. Letrozole co-treatment significantly suppressed oestradiol and follicle-stimulating hormone concentrations from stimulation day 5 and onwards, while increasing luteinizing hormone levels on stimulation day 5 and trigger day. The effect was more pronounced with a 5 mg dose of letrozole compared to a 2.5 mg dose (P < 0.05). Administration of 5 mg letrozole reduced the gonadotropin dose (P < 0.05) without negatively affecting the number of oocytes retrieved and subsequent embryo parameters (P > 0.05). The analysis of cumulative live birth rates showed rates of 29.4% in the letrozole 5 mg group, 27.5% in the letrozole 2.5 mg group, and 33.6% in the control group, with no statistically significant difference (P > 0.05). There were no reported pregnancy complications in the two letrozole groups. Additionally, there were no significant differences among the three groups in terms of gestational age and birth weight for both singleton and twin births.

Conclusion

This study indicates that the administration of letrozole in an antagonist protocol, at both 2.5 mg and 5 mg dosages, results in comparable clinical outcomes.

Effects of letrozole co-treatment on outcomes of gonadotropin-releasing hormone antagonist cycles in POSEIDON groups 3 and 4 expected poor responders

PURPOSE

To evaluate the effects of adjuvant letrozole administration on outcomes of gonadotropin-releasing hormone (GnRH) antagonist cycles with intra-cytoplasmic sperm injection in POSEIDON groups 3 and 4 expected poor responder women.

METHODS

This study was conducted by retrospective analysis of patients with expected poor ovarian response (POSEIDON groups 3 and 4) that underwent GnRH antagonist cycles with intra-cytoplasmic sperm injection between 2010 and 2020. A total of 488 patients with letrozole co-administration and 2564 patients without any adjuvant treatment that underwent GnRH antagonist cycles within the selected period of time were included in the study.

RESULTS

Implantation rates, clinical pregnancy rates and live birth delivery rates were significantly higher in letrozole administered patients in comparison to controls among POSEIDON group 3 women (0.39 ± 0.46 vs 0.27 ± 0.40, p = 0.01; 46.1% vs 33%, p = 0.014; 42.7% vs 31.5%, p = 0.034, respectively). Mean total doses of gonadotropins required per cycle were significantly lower in letrozole administered patients among both POSEIDON groups 3 and 4 women (2864.65 ± 878.47 IU vs 3757.27 ± 1088.89 IU, p < 0.001; 3286.06 ± 770.16 IU vs 3666.48 ± 959.66 IU, p < 0.001, respectively).

CONCLUSION

Adjuvant letrozole co-administration in intra-cytoplasmic sperm injection cycles following GnRH antagonist protocol appears to improve implantation, clinical pregnancy and live birth delivery rates in women with POSEIDON group 3 expected poor ovarian response.

Controlled ovarian hyperstimulation for poor ovarian responders undergoing in vitro fertilisation/intracytoplasmic sperm injection: a protocol for systematic review and Bayesian network meta-analysis

INTRODUCTION

Controlled ovarian hyperstimulation (COH) is the routine regimen used to generate a sufficient number of follicles during in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) treatment. Poor ovarian response is a challenge encountered by many clinicians during COH and poor ovarian responders (PORs) usually have higher follicle stimulating hormone levels, lower levels of anti-Mullerian hormone and few oocytes retrieved, which have been attributed mainly to advanced maternal age and poor follicle reserve or other reasons that could impair ovarian response during ovarian stimulation. Over the last few decades, researchers have proposed a series of strategies and ovarian stimulation protocols to improve pregnancy outcomes in patients with POR during their IVF/ICSI treatment. However, clinical decisions regarding COH protocols in PORs during IVF/ICSI treatment remain controversial. Traditional pairwise meta-analysis only allows the direct comparison of two protocols in COH for patients with POR. However, many of these COH protocols have not been compared directly in randomised controlled trials (RCTs). Thus, we aim to use network meta-analysis (NMA) to assess the clinical effectiveness and safety of COH protocols and to generate treatment rankings of these COH protocols for the most clinically important and commonly reported outcomes events.

METHODS AND ANALYSIS

The PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI, WanFang database and Chongqing VIP information databases will be searched for all RCTs of COH for POR women during IVF/ICSI from inception to 31 March 2020. Primary outcomes will include live birth rate and number of oocytes retrieved. Secondary outcomes will include ongoing pregnancy rate, clinical pregnancy rate, miscarriage rate, ovarian hyperstimulation syndrome rate, multiple pregnancy rate and cycle cancellation rate. Pairwise meta-analysis and Bayesian NMA will be conducted for each outcome. Subgroup analysis, meta-regression, and sensitivity analysis will be performed to assess the robustness of the findings. The generation of NMA plots and subsequent results will be performed by using R V.4.0.1. The assessment of confidence in network estimates will use the Confidence in Network Meta-Analysis)web application (see https://cinema.ispm.unibe.ch/).

ETHICS AND DISSEMINATION

This review does not require ethics approval and the results of the NMA will be submitted to a peer-review journal.

Does daily co administration of gonadotropins and letrozole during the ovarian stimulation improve IVF outcome for poor and sub optimal responders?

Background

Co-administration of letrozole during the first 5 days of ovarian stimulation was suggested to improve IVF outcomes in poor responders. We aimed to determine whether poor/sub-optimal responders might benefit from Letrozole co-treatment throughout the entire stimulation course.

Methods

We retrospectively reviewed the medical files of women who demonstrated poor (oocyte yield ≤3) and sub-optimal (4 ≤ oocyte yield ≤9) ovarian response during conventional multiple-dose antagonist stimulation protocols and were co-treated in a subsequent cycle with 5 mg Letrozole from the first day of stimulation until trigger day. A self-paired comparison between gonadotropins-only and gonadotropins-letrozole cycles was performed.

Results

Twenty-four patients were included. Mean patients’ age was 39.83 ± 4.60 and mean day-3-FSH was 12.77 ± 4.49 IU/m. Duration of stimulation and total gonadotropins dose were comparable between the two cycle groups. Peak estradiol levels were significantly lower in gonadotropins-letrozole cycles (2786.74 ± 2118.53 vs 1200.13 ± 535.98, p < 0.05). Number of retrieved oocytes (3.29 ± 2.15 vs 6.46 ± 3.20, p < 0.05), MII-oocytes (2.47 ± 1.65 vs 5.59 ± 3.20, p < 0.05), 2PN-embryos (1.78 ± 1.50, 4.04 ± 2.74, p < 0.05) and top-quality embryos (0.91 ± 0.97 vs. 2.35 ± 1.66, p < 0.05) were significantly higher in the gonadotropins-letrozole cycles. Clinical pregnancy rate in gonadotropins-letrozole cycles was 31.5%.

Conclusion

Letrozole co-treatment during the entire stimulation course improves ovarian response and IVF outcomes in poor/sub-optimal responders.