Recombinant LH supplementation improves cumulative live birth rates in GnRH antagonist protocol: a multi-center retrospective study using a propensity score-matching analysis.

Background: Luteinization hormone (LH) is critical in follicle growth and oocyte maturation. However, the value of recombinant-LH (r-LH) supplementation to recombinant-follicle stimulation hormone (r-FSH) during controlled ovarian stimulation in Gonadotrophin releasing hormone (GnRH) antagonist regimen is controversial. Methods: The multicenter retrospective cohort study recruited 899 GnRH antagonist cycles stimulated with r-LH and r-FSH in 3 reproductive centers, and matched to 2652 r-FSH stimulating cycles using propensity score matching (PSM) for potential confounders in a 1:3 ratio. The primary outcome was the cumulative live birth rate (CLBR) per complete cycle. Results: The baseline characteristics were comparable in the r-FSH/r-LH and r-FSH groups after PSM. The r-FSH/r-LH group achieved higher CLBR than the r-FSH group (66.95% VS 61.16%, p=0.006). R-LH supplementation also resulted in higher 2-pronuclear embryo rate, usable embryo rate, live birth rate in both fresh embryo transfer cycles and frozen-thawed embryo transfer (FET) cycles. No significant differences were found in the moderate and severe ovarian hyperstimulation syndrome (OHSS) rate, and cycle cancel rate in prevention of OHSS. Conclusions: R-LH supplementation to r-FSH in GnRH antagonist protocol was significantly associated with higher CLBR, live birth rate in fresh and FET cycles, and improved embryo quality without increasing OHSS rate and cycle cancel rate.