Effects of metformin on ovulation rate, hormonal and metabolic profiles inwomen with clomiphene-resistant polycystic ovaries: a randomized, double-blinded placebo-controlled trial

BACKGROUND: Metformin, an insulin-sensitizing agent, has been used successf ully as the first-line drug to induce ovulation in women with polycystic ov ary syndrome. There are, however, very few studies evaluating metformin tre atment in women with clomiphene citrate (CC)-resistant polycystic ovaries ( PCO). METHODS: Twenty infertile Chinese women aged < 40 years, who had ultr asound features of PCO and remained anovulatory on CC, were randomized by c omputer using the sealed envelope method to receive placebo or metformin 50 0 mg three times a day for 3 months. Hormonal and metabolic profiles were d etermined before the therapy and were repeated after 3 months for women who failed to become pregnant within this period. Clomiphene was then added fo r one cycle to those women who did not ovulate after taking placebo or metf ormin alone. RESULTS: The median ovulation rate in the placebo group was 0% (range: 0-50%) after placebo only and 6.9% (range: 0-50%) after placebo an d CC, whereas the corresponding rates in the metformin group were 0% (range : 0-22%) and 0% (range: 0-22%) respectively. There was no improvement in th e ovulation rate despite a significant reduction of body mass index, serum testosterone and fasting leptin concentrations in the metformin group. CONC LUSIONS: Metformin treatment may result in successful ovulation only in cer tain subgroups of these women.