This retrospective study aimed to compare the live birth rate and clinical pregnancy rate in natural cycle-frozen-thawed embryo transfer (NC-FET) with oral dydrogesterone as luteal phase support or without any drugs. Retrospective, cohort study. Totally 2657 NC-FET cycles allocated to two groups from the reproductive medical center at the University of Hong Kong-Shenzhen hospital from 2015 to 2023 and the Center of Reproductive Medicine, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine using data in 2023. One group of NC-FET cycles ( n = 1160) used oral dydrogesterone as LPS, the other group ( n = 1497) use no drugs. Significant differences were found in woman’s age, antral follicle account, E2 level on the day of Luteinizing hormone surge, the number of transferred embryo and the secondary infertility before propensity score matching (PSM). Thus 802 cycles in each group remained after PSM. Then no significant differences were found in each characteristic between two groups. No significant differences in live birth rate (27.930% vs. 32.173%, P = 0.064), clinical pregnancy rate (33.416% vs. 38.030%, P = 0.054), implantation rate (27.322% vs. 29.636%, P = 0.229), and miscarriage rate (16.418% vs. 15.635%, P = 0.798) were found between the control group and the study group after PSM. 30 mg/d oral dydrogesterone and no LPS revealed similar reproductive outcomes in NC-FET cycles in the study.
Ye et al. (Wed,) studied this question.