Los puntos clave no están disponibles para este artículo en este momento.
Background: Polycystic ovary syndrome (PCOS) is a leading cause of anovulatory infertility. In women undergoing frozen embryo transfer, the method of endometrial preparation (hormone replacement therapy HRT or mild ovarian stimulation MOS) can affect pregnancy outcomes. Letrozole-based MOS protocols may improve endometrial receptivity and reduce miscarriage rates by upregulating key implantation markers leukemia inhibitory factor, dickkopf-related protein 1, leukemia inhibitory factor receptor, fibroblast growth factor 22, integrin alpha V beta 3. Objective: This study aimed to compare the frozen embryo transfer outcomes in 2 endometrial preparation methods: HRT and MOS in infertile women with PCOS. Materials and Methods: This double-blind randomized trial included 100 infertile women with PCOS and frozen embryos who referred to Al-Zahra hospital, Tabriz, Iran between October 2024 and 2025. Participants were assigned to HRT or MOS for endometrial preparation. In HRT, oral estradiol followed by injectable progesterone was used; in MOS, letrozole + follicle-stimulating hormone stimulation continued until follicle > 17 mm and endometrium ≥ 7.5 mm, then human chorionic gonadotropin was given. Cleavage-stage transfer was performed in both groups, and pregnancy outcomes (chemical, clinical, and final) were compared. Results: The number of transferred embryos (p = 0.771) and their quality (types 1 and 2) (p = 0.857) were similar between groups. The number of chemical pregnancies in the MOS group (25 cases) was non-significantly higher than in the HRT group (20 cases) (p = 0.078). However, the number of clinical pregnancies (p = 0.045) and the number of successful pregnancies (p = 0.049) were significantly higher in the MOS group compared to the HRT group. Conclusion: This study showed that MOS achieved higher clinical and successful pregnancy rates than HRT in women with PCOS.
Hamdi et al. (Sat,) studied this question.