Does metformin augment the ovulation inducing effects of clomiphene in non-obese women with polycystic ovary syndrome?

To decide if metformin augments clomiphene response for ovulation induction in non-obese women with polycystic ovary syndrome, a prospective randomised placebo-controlled trial was undertaken among 27 patients, who were found eligible for this study following clinical assessment and basic investigations. Women with polycystic ovary syndrome, even when non-obese, has increased insulin-resistance and do not respond favourably when treated with clomiphene for ovulation induction. The hypothesis is that by improving insulin- resistance and thus reversing from hyperinsulinaemia towards normal insulin secretion will enhance the responsiveness of these women to ovulation inducing effects of clomiphene. In the metformin group there were 15 patients who were given metformin 500mg orally 8 hourly daily for initial 3 months whereas in the placebo group there were 12 patients who were given folic acid (as placebo) 5mg orally once daily for initial 3 months. Thereafter, all the 27 patients in both groups were treated with clomiphene 50mg orally once daily from day 2 for 5 days in each month for subsequent 3 months. However, metformin and folic acid was continued in the metformin group and placebo group respectively for these subsequent 3 months when these patients were being treated with clomiphene for ovulation induction. Ovulation, as the outcome measure, was assessed by serial transvaginal ultrasound scanning from day 8/ day 9 and serum progesterone estimation on the 7th or 8th day following the ultrasound evidence of ovulation. Ovulation is taken to have occurred when serum progesterone was > or =8 ng/ml. Ovulation was noted to have occurred in 71.11% of the 45 cycles studied in 15 patients in the metformin group whereas ovulation occurred in 11.11% of the 36 cycles studied in 12 patients in the placebo group. This difference was highly statistically significant (p < 0.001) by Fisher's exact test. It can be conducted that metformin augments the ovulation inducing effects of clomiphene in non-obese women with polycystic ovary syndrome.