Letrozole versus combined metformin and clomiphene citrate for ovulation induction in clomiphene-resistant women with polycystic ovary syndrome: a randomized controlled trial.Fertil Steril. 2010 Sep; 94(4):1405-9.FS
To compare the effect of letrozole with combined metformin and clomiphene citrate (CC) for ovulation induction in CC-resistant women with polycystic ovary syndrome (PCOS).
A randomized controlled trial.
University teaching hospital and a private practice setting.
Two hundred fifty anovulatory women (582 cycles) with CC-resistant PCOS.
Patients received 2.5 mg of letrozole daily (123 patients, 285 cycles) or combined metformin-CC (127 patients, 297 cycles) for three treatment cycles.
MAIN OUTCOME MEASURE(S)
Ovulation rate, number of follicles, serum E(2), serum P, endometrial thickness, pregnancy, and miscarriage rates.
Ovulation occurred in 185/285 cycles (64.9%) in the letrozole group versus 207/297 cycles (69.6%) in the combined metformin-CC group, without statistically significant difference. The total number of follicles was significantly more in the combined metformin-CC group (4.4+/-0.4 vs. 6.8+/-0.3). A nonsignificant increase in endometrial thickness on the day of hCG administration was observed in the letrozole group (9.5+/-0.2 mm vs. 9.1+/-0.1 mm). No statistically significant difference regarding the pregnancy rate (PR) was observed between both groups (14.7% vs. 14.4%).
Letrozole and combined metformin-CC are equally effective for inducing ovulation and achieving pregnancy in patients with CC-resistant PCOS.