Comparison of the GnRH agonist and antagonist protocol on the same patients in assisted reproduction during controlled ovarian stimulation cycles

Despite the fact that both gonadotropin-releasing hormone (GnRH) agonist and antagonist protocol are effective in suppressing the incidence of premature luteinizing hormone (LH) surges through reversibly blocking the secretion of pituitary gonadotropins, the exact impact of these two distinctive protocols on the clinical setting of patients for in vitro fertilization and embryo transfer (IVF-ET) treatment, however, remained controversial. We thus in the present report conducted a retrospective study to compare the impact of GnRH agonist and antagonist protocol on the same patients during controlled ovarian stimulation cycles. A total of 81 patients undergoing 105 agonist and 88 antagonist protocol were analyzed. We failed to detect a significant difference between two protocols for the difference in duration of ovarian stimulation, number of recombinant FSH (Gonal-F) ampoules used, number of oocytes retrieved, serum levels for estradiol (E2) and progestone (P), thickness of endometrium, and the zygote- and blastocyst-development rate. It is seemly that high quality embryo rate was higher in the antagonist protocol, but the data did not reach a statistical significance. Nevertheless, Implantation rate and clinical pregnancy rate were significantly higher in the antagonist protocol (10.64% and 30.26%, respectively) than that of the agonist protocol (5.26% and 15.82%, respectively). Our data also suggest that the GnRH antagonist protocol is likely to have the advantage for improving the outcome of pregnancy in those patients with a history of multiple failures for the IVF-ET treatment.