Abstract
OBJECTIVE: To optimize ovulation induction protocols for infertile women with PCOS, ovulation effect and adverse reactions of different doses of letrozole (2.5 vs 5.0 mg) combined sequentially HMG therapy were compared in infertility PCOS patients. METHODS: This open-label randomized controlled trial (RCT) included 174 infertile women aged 18-40 who met the Rotterdam criteria for PCOS at the Wuhan Union Hospital of China from May 2021 to January 2022. They were randomly assigned at a 1:1 ratio to 2.5 mg LE or 5.0 mg LE on cycle days 3-7 with sequential HMG injections (n = 87 for each). RESULTS: There is no difference in ovulation rate between LE (2.5 mg) + HMG group and LE (5.0 mg) + HMG group in infertile women with PCOS (85.1 vs 85.1%). The ongoing pregnancy rate was no different between the two groups (33.3 vs 25.3%). The percentage of type B endometrial tissues on HCG injection day was higher in the LE (2.5 mg) + HMG group (88.5% vs 69.0%). The monofollicular development rate was significantly higher in the LE (2.5 mg) + HMG group (67.8% vs. 46.0%). CONCLUSIONS: Application of 5.0 mg LE followed with HMG does not improve the pregnancy rate compared to 2.5 mg LE in infertile women with PCOS. An increased dose of LE to 5.0 mg may increase the risks of OHSS and multiple pregnancies. Therapy of LE (2.5 mg) + HMG may be a more beneficial and optimal treatment protocol for improving endometrial receptivity and promoting mono-follicle development for patients with PCOS.