Luteal phase support with progesterone in intrauterine insemination: a prospective randomized study

Objective: To determine the effect of vaginal progesterone as luteal support on pregnancy outcomes in infertile patients who undergo ovulation induction with gonadotropins and intrauterine insemination (IUI). Design: Prospective randomized trial. Setting: Tertiary referral center. Patient(s): About 398 patients with primary infertility were treated during 893 ovarian stimulation and IUI cycles from February 2010 to September 2012. Methods: All patients underwent ovarian stimulation with gonadotropins combined with IUI. Patients in the supported group received vaginal micronized progesterone capsules 200 mg once daily from the day after insemination until next menstruation or continuing for up to 8 weeks of pregnancy. Women allocated in the control group did not receive luteal phase support. Main outcome measure(s): Livebirth rate, clinical pregnancy rate and early miscarriage rate per cycle. Result(s): Of the 893 cycles, a total of 111 clinical pregnancies occurred. There were no significant differences between supported with progesterone and unsupported cycle in terms of livebirth rate (10.2% versus 8.3%, respectively, with a p value = 0.874) and clinical pregnancy rate (13.8% compared with 11.0% in unsupported cycle with a p value = 0.248). An early miscarriage rate of 3.6% was observed in the supported cycles and 2.7% in the unsupported cycles, with no significant differences between the groups (p value = 0.874). Conclusion(s): In infertile patients treated with mildly ovarian stimulation with recombinant gonadotropins and IUI, luteal phase support with vaginal progesterone is not associated with higher livebirth rate or clinical pregnancy rate compared with patients who did not receive any luteal phase support.