Effects of 100 IU versus 150 IU hCG supplementation on oocyte and embryo quality in patients aged ≥ 35 years: a propensity score-matched analysis.

The optimal dose of human chorionic gonadotropin (hCG) supplementation during controlled ovarian stimulation (COS) remains controversial, particularly in women of advanced reproductive age. To compare the efficacy and safety of 150 IU versus 100 IU daily hCG supplementation from stimulation day 6 in women aged ≥ 35 years undergoing fertilization/intracytoplasmic sperm injection (IVF/ICSI). In this retrospective cohort study, we analyzed data from 438 patients aged ≥ 35 years undergoing IVF at a single center. Propensity score matching was performed at a 1:1 ratio, yielding 192 patients per group who received either 100 IU or 150 IU daily hCG supplementation from stimulation day 6 during GnRH antagonist cycles. After propensity score matching, baseline characteristics were comparable between groups. The 150 IU group yielded significantly more total oocytes (9.23±6.60 vs 7.79±5.52, p<0.001). However, the number of mature oocytes (6.25±5.12 vs 5.66±4.58) and day 3 embryos (5.22±4.62 vs 4.80±3.96) did not differ significantly between groups. Total FSH dose was similar (2664.84±141.91 vs 2666.02±142.51 IU, p=0.936). Only one case of moderate ovarian hyperstimulation syndrome occurred in the 150 IU group. In women aged ≥ 35 years, while 150 IU daily hCG supplementation from stimulation day 6 safely increased total oocyte yield compared to 100 IU, it did not significantly improve mature oocyte numbers or embryo development.