Efficacy comparison of GnRH antagonist protocol and GnRH long protocol for the patients undergoing fresh embryo transfer

Objective：To compare the clinical effect between gonadotrophinreleasing hormone (GnRH) antagonist protocol and GnRH agonist long protocol in patients obtaining fresh embryo transfer. Methods：Clinical data of patients in the fresh embryo transfer cycle were analyzed retrospectively. Main clinical outcomes including superovulation and pregnant rates were compared. Results：A total of 706 cases were selected, 637 patients received GnRH agonist long protocol, and 69 patients received antagonist protocol. Compared with agonist group, the patients in antagonist group had significantly shorter duration of gonadotropin (［10.55±1.38］ d vs ［11.20±1.84］ d), fewer doses (［1 699.50±611.25］ U vs ［2 196.75±765.75］ U, P＜0.05), more oocytes (12.11±5.20 vs 9.69±3.86, P＜0.05), and more MⅡoocytes (10.15±4.65 vs 8.26±3.50, P＜0.05). However, there was no significant difference in thickness of endometrium, fertilization rate, implantation rate, and pregnant rate between the two groups. Conclusions：Compared with the long GnRH agonist protocol, the GnRH antagonist protocol can bring out a substantial increase in the number of good quality embryos among the patients receiving fresh embryo transfer, but shows no advantage in pregnant rate.