OBJECTIVETo compare the pituitary down-regulatory effects of the two gonadotropin-releasing hormone agonists Alarelin and Triptorelin in the long protocol of ovulation induction in in vitro fertilization and embryo transfer (IVF-ET).

METHODSWe included in this study 122 patients aged 24-39 years treated by IVF-ET for secondary infertility, with 10-20 pre-antral follicles and obstruction of the fallopian tube. Seventy-eight of them received Alarelin, and the other 44 Triptorelin. Comparative analyses were made on the pituitary down-regulatory effects of the two gonadotropin-releasing hormone agonists and the clinical outcomes of IVF-ET.

RESULTSNo premature LH surge and ovulation, nor severe hyperovarian stimulation syndrome was found in either group. There were no significant differences between the two groups in the mean dose and duration of gonodatropin treatment, the numbers of oocytes retrieved, mature oocytes and top-quality embryos, and the rates of 2PN, multi-sperm fertilization, cleavage, embryo transfer, embryo implantation, clinical pregnancy and early miscarriage (P > 0.05), but the rate of cancelled cycles was significantly higher in the Triptorelin than in the Alarelin group (P < 0.05).

CONCLUSIONAlarelin and Triptorelin can achieve similar pituitary down-regulatory effects and clinical outcomes in IVF-ET when used in the long protocol of ovulation induction.