Minimum dose of hCG to trigger final oocyte maturation and prevent OHSS in a long GnRHa protocol

This paper was aimed to study the minimum dose of human chorionic gonadotropin (hCG) to effectively trigger maturation of oocytes and prevent ovarian hyperstimulation syndrome (OHSS) in a series of hyper-responders treated with a long gonadotropin releasing hormone agonist (GnRHa) protocol. Six women at high risk of developing severe OHSS in a long GnRHa protocol were enrolled into this study. Serum hormone levels on the day of and after hCG administration, antral follicle count, oocyte retrieval number and quality were determined. In total, 6 women aged between 29 and 36 years and at risk of developing severe OHSS, received 2000 U hCG. Five of them were treated with coasting for 1 day and the rest one for 4 days. The mean number of oocytes collected was 19 (range 14-27) and the fertilization rate per collected oocyte was 72.81%. Of the 6 women in the study, only one cancelled embryos transfer and all embryos were frozen, and then she delivered two health boys on term in the subsequent frozen-thawed embryo transfer (FET) cycle. Pregnancies and births were achieved in 3 patients out of 5 in vitro fertilization-embryo transfer (IVF-ET) cycles. No woman developed moderate or severe OHSS. Triggering with 2000 U hCG is feasible to prevent OHSS in unpredicted hyper-responders undergoing IVF in a long GnRHa protocol.