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

Ashraf Moini, Moini A, Zohreh Lavasani, Lavasani Z, Ladan Kashani, Kashani L, Mojtahedi MF, Maryam Farid Mojtahedi, Nazila Yamini, Yamini N
International journal of reproductive biomedicine · 2019 · vol. 17(9) , pp. 653–660 · doi:10.18502/ijrm.v17i9.5101 · PMID:31646260 · PMC6804330
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This randomized trial found that adding letrozole to gonadotropin-releasing hormone antagonist protocols significantly increased retrieved oocytes and reduced medication dosage in poor ovarian response patients undergoing assisted reproduction.

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This double-blind randomized clinical trial evaluated the efficacy of adding letrozole to a GnRH antagonist ovarian stimulation protocol for women diagnosed with poor ovarian response. The study excluded patients with endometriosis and compared outcomes between those receiving letrozole alongside gonadotropins versus those receiving a placebo, focusing on metrics such as oocyte retrieval rates and cycle cancellation. Results indicated that while letrozole significantly reduced the duration of stimulation and total gonadotropin consumption, it did not yield statistically significant improvements in the number of oocytes retrieved or clinical pregnancy rates compared to the control group. Relevance to endometriosis: the paper explicitly excludes patients with endometriosis from its study population, meaning the findings apply only to non-endometriosis-related poor responders.

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Abstract

BACKGROUND: Ovarian stimulation (OS) for poor ovarian response (POR) patients is still a major challenge in assisted reproductive techniques. Aromatase inhibitors as co-treatment in antagonist protocol are suggested to these patients, but there are controversial reports. OBJECTIVE: To evaluate the effectiveness Letrozole (LZ) as adjuvant treatment in gonadotropin-releasing hormone (GnRH)-antagonist protocol in POR patients undergoing in vitro fertilization/ intracytoplasmic sperm injection cycles. MATERIALS AND METHODS: This double-blind randomized clinical trial was conducted in Arash women's hospital. One hundred sixty infertile women with POR based on Bologna criteria were allocated into two groups randomly: LZ + GnRH-antagonist (LA) and placebo + GnRH-antagonist (PA) groups. In the experimental group, the patients received 5 mg LZ on the first five days of OS with 150 IU of recombinant human follicle-stimulating hormone (rFSH) and 150 IUof human menopausal gonadotropin (HMG). The cycle outcomes were compared between groups. RESULTS: The total number of retrieved oocytes and the metaphase II oocytes in LA-treated group were significantly higher than those in the control group (p = 0.008, p = 0.002). The dosage of hMG used and the duration of OS and antagonist administration in LZ-treated group were significantly lower than those of the control group. The number of patients with no oocyte, in the control group, was higher than the LZ-treated group, and the clinical pregnancy rate in LA-treated group (25%) was higher than the control group (18%); however, the differences were not significant statistically. CONCLUSION: Adding 5 mg of LZ to rFSH/hMG antagonist protocol may improve the in vitro fertilization/intracytoplasmic sperm injectioncycle outcome in POR patients.
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In conclusion, according to the results of the current clinical trial, adding LZ to the rFSH/hMG antagonist protocol may improve the outcome of the IVF/ICSI cycles in patients with POR. In addition, considering the evidence provided with previous studies and current trial, we suggested designing future studies to evaluate the effect of adjunctive use of low-dose LZ in conventional OS regimes on IVF/ICSI outcomes in patients with unexplained infertility, endometriosis, and PCOS diagnosis. The comparison ofdemographic and clinical characteristics of study participants between groups Variables were compared between groups and presented as mean ± SD; data were compared between groups and presented as n (%) ≤ 0.05 was considered statistically significant No.: Number; FSH: Follicle-stimulating hormone; LH: Luteinizing hormone; TSH: Thyroid-stimulating hormone; AMH: Anti-müllerian hormone; E 2 : estradiol; P: Progesterone . The comparison of ovarian stimulation and cycle outcomes between the study groups Variables were compared between groups and presented as mean ± SD; data were compared between groups and presented as n (%) ≤ 0.05 was considered statistically significant hMG: Human menopause gonadotropin; rFSH: Recombinant follicle-stimulating hormone; No.: Number

Coi Statement

There are no conflicts of interest to declare.

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