Timing and duration of use of GnRH antagonist down-regulation for IVF/ICSI cycles have no impact on oocyte quality or pregnancy outcomes

PURPOSE: To evaluate whether oocyte quality, implantation and pregnancy outcomes in in vitro fertilization (IVF)/intra-cytoplasmic sperm injection (ICSI) are related to the duration of gonadotropin-releasing hormone (GnRH)-antagonist use or the timing of its initiation. METHODS: Retrospective cohort study of 178 conventional IVF/ICSI cycles. All patients underwent ovarian stimulation with gonadotropins and GnRH-antagonist for pituitary down-regulation. Spearman correlations and logistic regression were used for statistical analysis. RESULTS: There was no correlation between the duration of use or the timing of initiation of GnRH-antagonist with oocyte quality or implantation and pregnancy outcomes. Oocyte quality was influenced by the peak estradiol. Implantation was influenced by the patient's age. Early pregnancy loss, by the endometrial thickness on human chorionic gonadotropin-day. Ongoing pregnancy was independent from the variables evaluated. CONCLUSIONS: GnRH-antagonist duration of use or starting day did not influence oocyte quality, implantation rates, and pregnancy rates. We hypothesize that a follicle stimulating hormone/luteinizing hormone dose increase when antagonist was started, may have had an impact on our findings.