Efficacy of luteal phase support with vaginal progesterone in intrauterine insemination: a systematic review and meta-analysis

To evaluate the efficacy of luteal phase support with vaginal progesterone in women undergoing intrauterine insemination (IUI). Systematic review and meta-analysis. Randomized controlled trials (RCT) comparing supplementation of luteal phase with vaginal progesterone among women undergoing IUI versus a control group were included. The main outcome assessed was live birth rate. Five RCT met the inclusion criteria. In all 1,271 patients were included (951 IUI cycles in the progesterone group, 935 in the control group). Women treated with vaginal progesterone achieved significantly higher live birth rate (risk ratio [RR] 1.94, 95 % confidence interval [CI] 1.36 to 2.77,), and clinical pregnancy rate (RR 1.41, 95 % CI 1.14 to 1.76) as compared with controls. In the subgroup analysis per stimulation protocol, this beneficial effect of receiving progesterone was only observed in the group stimulated with gonadotropins (RR 2.28, 95 % CI 1.49 to 3.51), compared to the group stimulated with clomiphene citrate (CC) (RR 1.30, 95 % CI 0.68 to 2.50). No differences were observed in the miscarriage and multiple pregnancy rates. The supplementation of luteal phase with vaginal progesterone significantly increases live birth among women undergoing IUI when receiving gonadotropins for ovulation induction. Women receiving CC to induce ovulation do not seem to benefit from this treatment.