OBJECTIVETo evaluate the application of gonadotrophin-releasing hormone antagonist (GnRH-ant) in patients with risk of poor response to controlled ovarian stimulation in IVF-ET.

METHODSClinical data of 48 patients undergoing IVF with or without ICSI were retrospectively analyzed. Among them 24 patients were allocated to the GnRH-ant protocol and 24 to the long gonadotrophin-releasing hormone agonist (GnRH-a) protocol. The duration of down-regulation, duration of stimulation, amps of gonadotropin estradiol level on hCG day, number of oocytes retrieved, fertilization rate, total embryos obtained, high quality embryo obtained, embryos transferred, embryos frozen, implantation rate per transfer, clinical pregnancy rate per transfer, embryo survival rate, clinical pregnancy rate per frozen embryos transfer and per cycle were compared between two groups.

RESULTThe duration of down-regulation, duration of stimulation, the amps of gonadotropin were significantly lower in the antagonist group than those in agonist group (P <0.001, <0.05, <0.05), the estradiol level on hCG day, the number of oocytes retrieved were significantly lower in the antagonist group than those in the agonist group (P<0.05, <0.05). No significant differences were noted in fertilization rate, total embryos obtained, high quality embryo obtained, embryos transferred, embryos frozen, implantation rate per transfer, clinical pregnancy rate per transfer, embryo survival rate, clinical pregnancy rate per frozen embryos transfer and per cycle.

CONCLUSIONCompared with long GnRH-a protocol, the GnRH-ant protocol in patients with risk of poor response can reduce the dosage of gonadotropin and shorten the duration of stimulation, although the estradiol level on hCG day and the number of oocytes retrieved are lower, which does not affect the implantation rate and clinical pregnancy rate.