Letrozole vs. clomiphene citrate in patients with ovulatory infertility.

Author(s): Bayar U, Tanriverdi HA, Barut A, Ayoglu F, Ozcan O, Kaya E

Affiliation(s): Department of Obstetrics and Gynecology, University of Karaelmas, Zonguldak, Turkey. ulkubayar@yahoo.com

Publication date & source: 2006-04, Fertil Steril., 85(4):1045-8. Epub 2006 Mar 9.

Publication type: Randomized Controlled Trial

OBJECTIVE: To compare the effectiveness of letrozole and clomiphene citrate (CC) in ovulatory patients with borderline male factor infertility, early stage endometriosis, and unexplained infertility. DESIGN: Prospective quasi-randomized trial. SETTING: University infertility clinic. PATIENT(S): Forty-six consecutive patients with ovulatory infertility were recruited. Twenty-five patients (67 cycles) were given CC and 21 patients (52 cycles) were given letrozole. Both drugs were given orally on days 3-7 of menses. INTERVENTION(S): Letrozole, CC, ovulation induction, IUI, timed intercourse. MAIN OUTCOME MEASURE(S): Number of follicles, endometrial thickness, and pregnancy rates. RESULT(S): The median serum E2 concentration on the day of hCG administration in the letrozole and CC groups were 191.5 pmol/L and 476.0 pmol/L, respectively. The median endometrial thickness on the day of hCG were 8 mm in both groups. Ovulation occurred in 81% (42/52) of the letrozole-treated and 85% (57/67) of the CC-treated patients. Pregnancy rate (PR) per cycle was 9% (5/52) in the letrozole group and 12% (8/67) in the CC group. CONCLUSION(S): Letrozole and CC have comparable effectiveness in ovulatory patients with borderline male factor infertility, early stage endometriosis, and unexplained infertility.