A randomized controlled trial evaluating the effect of ethinyl estradiol during clomiphene citrate cycles among women with polycystic ovary syndrome.

OBJECTIVE

To investigate the effects of low-dose ethinyl estradiol (EE) on the clinical pregnancy rate among women with polycystic ovary syndrome (PCOS) undergoing ovulation induction with clomiphene citrate (CC).

METHODS

Between March 12, 2011, and February 10, 2013, a randomized, double-blind, placebo-controlled trial was conducted at the Royan Institute Research Center, Tehran, Iran, among women with PCOS who were aged 25-30 years, were undergoing their first intrauterine insemination cycle, and had a history (≥2 years) of infertility, oligomenorrhea, or amenorrhea. Participants were randomly allocated to receive EE (0.05 mg daily for 5 days) or placebo, co-administered with CC cycles (100 mg daily for 5 days). The primary outcome was clinical pregnancy rate. Analyses were per protocol: patients who discontinued the intervention were excluded.

RESULTS

Analyses included 45 women who received CC and EE, and 50 women who received CC and placebo. The number of women who achieved a clinical pregnancy was higher among participants who received CC and EE (13 [29%]) than among those in the control group (5 [10%]; P =0 .02). No adverse effects of EE were reported.

CONCLUSION

The combination of CC and EE seems to increase the clinical pregnancy rate among women with PCOS undergoing intrauterine insemination. ClinicalTrials.gov:NCT01219101.