GnRH antagonist improved blastocyst quality and pregnancy outcome after multiple failures of IVF/ICSI-ET with a GnRH agonist protocol

Background: To determine the efficacy of a gonadotrophin-releasing hormone( GnRH) antagonist, cetrorelix, in improving the quality of embryos and pregnancy outcome, we performed a study in patients with a history of multiple failures of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles with a GnRH agonist (GnRHa) long protocol. Methods: Forty women with no live births after conventional IVF or ICSI embryo transfer (ET) and subsequent blastocyst transfer (BT) with a GnRHa long protocol entered this study. The treatment protocol consisted of a daily dose of clomiphene citrate 100 mg for 5 days and gonadotrophin injections daily from cycle day 4 onward. Cetrorelix, 0.25 mg/day, was started when the leading follicle reached 14 mm. Induction of ovulation was triggered with human chorionic gonadotrophin (HCG) (N=36) or GnRHa (N=4). It was possible to perform BT in 38 patients. Results: Comparison of the results with the results for BT with the previous GnRHa protocol showed no significant differences in number of oocytes retrieved or the zygote- and blastocyst-development rate. With the cetrorelix protocol, however, number of patients whose embryos had developed to at least one expanded blastocyst on day 5 was significantly higher than with the GnRHa protocol (25 vs. 9) (p<0.001), and 16 of the women became pregnant (42.1%), with 7 delivering 9 infants, 4 ending in abortion (25%), and 5 in progressing. Conclusions: The use of a GnRH antagonist in controlled ovarian hyperstimulation improves the outcome of pregnancy of patients with a history of multiple failure of IVF/ICSI-ET in a GnRHa protocol, most likely due to improvement of the quality of the blastocysts generated.