Effect of pretreatment oral contraceptives on fresh and cumulative live birth in vitro fertilization outcomes in ovulatory women.

OBJECTIVE:To evaluate the impact of oral contraceptives (OC) on live birth rate (LBR) following a fresh embryo transfer and cumulative live birth rate (cLBR) in normal ovulatory women undergoing in vitro fertilization (IVF). DESIGN:Retrospective cohort study. SETTING:Reproductive center. PATIENTS:A total of 3,110 normo-ovulatory women aged 20-40 years undergoing IVF either using or not using OC pretreatment in their first autologous cycle. INTERVENTION(S):Patients initiated gonadotropins for their IVF cycle either after a spontaneous menses or following OC pretreatment, which was at the discretion of the provider or according to patients preference. MAIN OUTCOME MEASURE(S):The primary outcomes were LBR after fresh transfer (fLBR) and cLBR. RESULTS:fLBR was significantly lower in women using OC compared to those not (42.6% vs. 52.8%). Although LBR after frozen embryo transfer cycles were similar (42.7% vs. 41.1%), cLBR was significantly lower in women using OC (62.8% vs. 67.6%). Multivariate logistic and COX regression analysis adjusting for baseline characteristics demonstrated that IVF cycle synchronization with OC was significantly associated with a lower fLBR (adjusted odds ratio 0.73, 95% confidence interval 0.62-0.86) and cLBR (adjusted hazard ratio 0.89, 95% confidence interval 0.80-0.98). CONCLUSIONS:Pretreatment OC use is associated with a reduction in fLBR and cLBR.