Duration of progesterone-in-oil support after in vitro fertilization and embryo transfer: A randomized, controlled trial

Objective: To determine the efficacy of a short P-in-oil protocol (11 days) in comparison with a traditional P-in-oil protocol (6 weeks) after IVF and embryo transfer. Design: Prospective randomized, controlled trial. Setting: Tertiary referral reproductive medicine unit. Patient(s): The first IVF-embryo transfer cycle of women ≤37 years old. Intervention(s): Either the standard protocol, 50 mg of IM P-in-oil daily for 6 weeks (group 1) or the study protocol, 50 mg of IM P-in-oil daily for 11 days (group 2). Main Outcome Measure(s): Clinical pregnancy, ongoing pregnancy, and live birth rates. Result(s): One hundred one patients were enrolled (48 in group 1, 53 in group 2). Mean age (31.8 years vs. 32.7 years) and reasons for infertility were not different between the groups. Despite higher embryo quality in group 1 than in group 2 (60.3 vs. 51.6), clinical (63.0% vs. 62.7%) and ongoing (58.7% vs. 51.0%) pregnancy rates (PR) were not significantly different. Live birth rates (52.2% vs. 49.0%) were not significantly different. Conclusion(s): Pregnancy and live birth rates were not different between the two groups, suggesting that the common practice of lengthy (≥6 weeks) P support of IVF pregnancies may be unnecessary.