The effect of progesterone supplementation on pregnancy rates in controlled ovarian stimulation and intrauterine insemination cycles: a randomized prospective trial

Abstract Objective To evaluate the effect of vaginal progesterone as luteal phase support on pregnancy rates in controlled ovarian stimulation and intrauterine insemination cycles in couples with unexplained or mild male factor infertility. Study design 290 Patients who met the inclusion criteria were included in a prospective randomized controlled trial. All patients underwent controlled ovarian stimulation and intrauterine insemination: 148 patients were randomized to start with a supported cycle and 142 patients with an unsupported cycle. In supported cycles, patients received vaginal progesterone once daily from the day after insemination until 12 weeks of pregnancy or, in non-pregnant women, for 14 days. No progesterone was given during unsupported cycles. The main outcome measures were clinical pregnancy rates per cycle. Results In total, 148 cycles with luteal phase support and 142 cycles without luteal phase support were performed. The clinical pregnancy rates per cycle were higher for cycles with luteal phase support than for the unsupported cycles (24.3% vs. 14.1% respectively, p  = 0.027). Conclusion The use of vaginal suppositories as luteal phase support significantly improved clinical pregnancy rates in controlled ovarian stimulation and intrauterine insemination in patients with unexplained or mild male factor infertility.