Low-dose GnRH antagonist protocol is as effective as the long GnRH agonist protocol in unselected patients undergoing in vitro fertilization and embryo transfer

The present retrospective and controlled comparative study was designed to evaluate the pregnancy rate achieved using a modified, fixed, multiple-dose 0.125 mg gonadotropin-releasing hormone (GnRH) antagonist protocol with the long GnRH agonist protocol as the control group. One hundred and twenty unselected women between 30 and 40 years of age, in their first cycle of IVF/ICSI, with a baseline follicle-stimulating hormone (FSH) <10 IU and an antral follicle count >3 were assigned into two groups: (1) the study group received 0.125 mg of cetrorelix daily starting on Day 6 of stimulation; and (2) the control group received leuprolide daily starting in the mid-luteal phase of the preceding cycle. Both groups were given a flexible dose of recombinant FSH for stimulation. An ongoing pregnancy rate of more than 12 weeks was the primary outcome measure of the study. Primary and secondary outcomes were comparable in both groups. A shorter duration of stimulation, a lower dosage of recombinant FSH consumption and a thinner endometrium on the day of human chorionic gonadotropin administration were all observed in the GnRH antagonist group. A dosage of 0.125 mg GnRH antagonist protocol was effective for these unselected patients during IVF/ET.