Comparison of the cumulative live birth rates after 1 in vitro fertilization cycle in women using gonadotropin-releasing hormone antagonist protocol vs. progestin-primed ovarian stimulation: a propensity score–matched study

Abstract

To determine whether gonadotropin-releasing hormone (GnRH) antagonist protocol can improve cumulative live birth rates (CLBRs) and shorten the time to live birth (TTLB) in unselected patients compared with progestin-primed ovarian stimulation (PPOS). A propensity score-matched retrospective cohort study design. Tertiary-care academic medical center. A total of 6,520 women with infertility aged 20-50 years were included. Patients underwent either the GnRH antagonist protocol (n = 5,004) or PPOS (n = 1,516) on the basis of the assessment of the attending physicians. One-to-one propensity score matching was performed with a caliper of 0.02. Women who were not matched were excluded from the analyses. The CLBR of which the ongoing status had to be achieved within 22 months from the day of ovarian stimulation and TTLB. Each group comprised 1,424 couples after propensity score matching, and the baseline demographic characteristics of the couples after matching were comparable between the 2 groups. The cycle cancellation rate was significantly lower in the GnRH antagonist group than in the PPOS group (12.9% vs. 19.6%). The implantation rate, clinical pregnancy rate, ongoing pregnancy rate, and live birth rate per transfer were comparable between the 2 groups. However, CLBRs after 1 complete IVF cycle were significantly higher in the GnRH antagonist group than in the PPOS group (36.0% vs. 32.2%; Risk ratio = 1.12; 95% confidence interval [CI], 1.01-1.24). The average TTLB was significantly shorter in the GnRH antagonist group than in the PPOS group (9.3 months vs. 12.4 months). Using the Kaplan-Meier analysis, the cumulative incidence of ongoing pregnancy leading to live birth was significantly higher in the GnRH antagonist group than in the PPOS group (85.1% vs. 66.1%, Log-rank test). A Cox proportional hazard model revealed that women who underwent the antagonist protocol were 2.32 times more likely to achieve a live birth than those who used PPOS (hazard ratio [HR] = 2.32; 95% CI, 1.91-2.83). Subgroup analysis revealed that women who used the antagonist protocol were more likely to achieve a live birth than women who used PPOS across the 3 antral follicle count (AFC) strata (AFC ≤ 5, AFC 6-15, and AFC > 15), 2 age strata (<35 and ≥35 years), and first cycle or repeated cycle. The difference was greatest among women whose AFC was ≤5 and who were aged ≥35 years, effectively becoming smaller in the group with high ovarian reserve and younger age. In unselected women undergoing IVF, the GnRH antagonist protocol was associated with a higher CLBR and a shorter TTLB compared with PPOS.