Comparison between Clomiphene citrate and Metformin for induction of ovulatory cycles in infertile nonobese women with Polycystic Ovary Syndrome

Between January 2007 and January 2009 at the Obstetric and Gynecologic Clinic of Catania University, 36 infertile anovulatory women with micropolycystic ovaries, aged between 21 and 35 years (mean age 28.8 +/- 4.3), were enrolled with the aim to evaluate the efficacy of clomiphene and metformina administration for ovulation induction. The patients were randomly divided into two groups. One group of 19 patients was treated with clomiphene citrate for 5 days at a dose of 50 mg/day in the first cycle and increased to 150 mg/day in subsequent cycles if ovulation was not achieved. The second group of 17 patients was treated with a starting dose of metformin of 500 mg twice daily, that was gradually increased to target dose of 850 mg/two times daily. Six cycles of treatment were made up for both groups. The ovulation rates were statistically similar in both groups: 67% in clomiphene group and 63.5% in metformin group. After 6 months of treatment, the pregnancy rate was higher among women treated with metformin (62.5%) than in those treated with clomiphene (33.3%). The miscarriage rate was higher in clomiphene group (33.3% versus 10%). The rate of live births was 66.6% and 90%, respectively.