Abstract: Objective To investigate the effect of Yunkang granules on pregnancy outcomes in frozen-thawed embryo transfer(FET). Methods A retrospective analysis was conducted on the clinical data of 2,610 FET cycles performed in Institute of Women, Children and Reproductive Health, Shandong University from January 2021 to December 2023. Patients were divided into the treatment group(n=782)and the control group(n=1,828)based on whether they took Yunkang granule. Pregnancy outcomes were compared between the two groups. Additionally, subgroup analyses were performed based on the FET protocols, that is, natural cycle, hormone replacement cycle, ovulation induction cycle, and down-regulation hormone replacement cycle. Results The clinical pregnancy rate in the treatment group(55.88%)was significantly higher than that in the control group(51.58%), with a statistically significant difference ［OR(95%CI)=1.26(1.04-1.53), P=0.016］. No statistically significant differences were observed in other pregnancy outcomes between the two groups. In the ovulation induction protocol, the clinical pregnancy rate and ongoing pregnancy rate in the treatment group(63.08%, 53.85%)were significantly higher than those in the control group(44.57%, 32.57%), with a statistically significant difference ［OR(95%CI)=1.89(1.02-3.50), P=0.044; OR(95%CI)=2.33(1.26-4.33), P=0.007］. However, no statistically significant differences were observed in pregnancy outcomes between the treatment group and the control group in the natural cycle, hormone replacement cycle, and down-regulation hormone replacement cycle. Conclusion Yunkang granules can improve clinical pregnancy rates and pregnancy outcomes, particularly in the ovulation induction protocol of the FET cycles.

Key words: Yunkang granule, Frozen-thawed embryo transfer, Luteal support, Pregnancy outcome