Evaluation of gonadotropin-releasing hormone agonist and antagonist protocols on pregnancy outcomes in POSEIDON groups 3 and 4: A randomized controlled trial.

Background: Women with low ovarian reserve are the capable part of people who refer to infertility centers, this study compares 2 treatment protocols in cases with low ovarian reserve.

Objective: This study aimed to compare the efficacy of gonadotropin-releasing hormone (GnRH) agonist and GnRH-antagonist protocols in women with diminished ovarian reserve (DOR) in POSEIDON groups 3-4 undergoing in assisted reproductive technology (ART).

Materials and methods: This randomized clinical trial enrolled 158 infertile women with diminished ovarian reserve undergoing ART at the Research and Clinical Center for Infertility, Yazd, Iran from January to October 2024. Women were randomly assigned to either a GnRH-antagonist (n = 84) or a long GnRH-agonist (n = 74). Primary outcomes included clinical pregnancy and secondary outcomes were chemical pregnancy, early abortion rate, ongoing pregnancy, and implantation rate.

Results: No significant differences were observed in baseline values between groups. The GnRH-agonist group had a longer stimulation duration (12.23 vs. 10.60 days, p $<$ 0.001) and a higher total gonadotropin dose (4588.84 vs. 3225.67 IU, p $<$ 0.001) compared to the antagonist group. Clinical pregnancy rates (17.8% vs. 15.8%, p = 0.810) and live birth rates (11.1% vs. 13.2%, p = 0.775) were comparable between the agonist and antagonist groups.

Conclusion: According to acquired data, the GnRH-antagonist and long GnRH-agonist protocols resulted in similar ART outcomes. The antagonist protocol was associated with shorter stimulation and lower gonadotropin consumption. As a result, the antagonist protocol was found to be more cost effective. Larger studies are needed to confirm these results and determine the optimal protocol for this woman group.