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.