A randomized controlled trial evaluating metformin pre-treatment and co-administration in non-obese insulin-resistant women with polycystic ovary syndrome treated with controlled ovarian stimulation plus timed intercourse or intrauterine insemination.

BACKGROUND There are few data in the literature regarding the utility of metfomin before and during gonadotrophin administration in women with polycystic ovary syndrome (PCOS). The aim of the present study was to assess the effect of the pre-treatment and co-administration of metformin in infertile PCOS women treated with controlled ovarian stimulation (COS) followed by timed intercourse (TI) or intrauterine insemination (IUI). METHODS Seventy insulin-resistant primary infertile women with PCOS were randomized to receive metformin cloridrate (850 mg twice daily; group A) or placebo tablets (two tablets daily; group B) for 3 months. Three trials of COS using highly purified urinary FSH (hpFSH) plus TI/IUI were performed. Number of ampoules of gonadotrophin used, duration of the ovarian stimulation, cycle cancellation, ovulation, pregnancy, abortion, live birth, mono-ovulatory cycles, multiple pregnancies and ovarian hyperstimulation syndrome (OHSS) rates were assessed. RESULTS No difference between groups was detected in ovulation, cycle cancellation, pregnancy, abortion, live birth, multiple pregnancies and OHSS rates. The mono-ovulatory cycle rates were significantly (P = 0.002) more frequent in group A than in group B, whereas the days of stimulation for non-cancelled cycles and the number of vials of gonadotrophins used were significantly (P < 0.001) higher in group A than in group B. CONCLUSION In insulin-resistant women with PCOS, metformin pre-treatment and co-administration with hpFSH increases the mono-ovulatory cycles.