Volume 3 No. 3, July 2008

Prospective, Randomized, Comparative Clinical Study of the Efficacy of Letrozole and Clomiphene Citrate as Adjuvants to Follicle-Stimulating Hormone in Superovulation
Zakaria Sanad1, Hamid Ellakwa1, Sherif Abd El-Salam1, Said Saleh1, Tarek Sayed1, Osama El-Kelani1, Mehany Abd El-Sattar1 & Dina El-Khouli2

Obstetrics & Gynecology Departments, Faculty of Medicine, Menoufiya1 and Tanta2 Universities, Egypt

Tanta Med. Sc. J 2008; 3(3):127-133
Article type: Original article

Aim: Prospective, randomized, comparative clinical study to compare the efficacy of the aromatase inhibitor letrozole and clomiphene citrate (CC) as adjuvants to follicle-stimulating hormone (FSH) in superovulation. Patients & Methods: A total of 120 patients from outpatient clinic of Menoufiya University hospital with unexplained or mild male factor infertility were randomized to receive either letrozole (59 patients) or CC (61 patients) as adjuvants to FSH. From day 3 to 7 of the cycle 2.5 mg/d letrozole or 100 mg/d CC were administered followed by 75 IU/d FSH starting on day 7 until the day of human chorionic gonadotropin (hCG). Ovulation was triggered with 10,000 IU of hCG when the leading follicle (s) reached 18 mm in diameter. A single intrauterine insemination (IUI) was performed 36 h later. Ovarian (estradiol (E2) levels and number of follicles) and endometrial (endometrial thickness) response and pregnancy outcome were the main measures. Results: The number of mature preovulatory follicles (1.9 + 0.7 vs. 2.2 + 0.5, P<0.0001) and the peak E2 level (791 + 163 vs. 1137 + 192 pg/ml, P<0.0001) were significantly higher in the CC group than in the letrozole group. A significantly higher endometrial thickness was observed on the day of hCG in the letrozole group (9.1 + 1.2 vs. 7.7 + 1.4 mm, P<0.0001). There was no significant difference between groups in clinical pregnancy rates (38.4% in the letrozole and 31.3% in the CC groups). In contrast, the abortion rate was significantly higher in the CC group (42% vs. 13%, P=0.04). Conclusion: The aromatase inhibitor letrozole appears to be a good alternative to CC in superovulation therapy. Benefits of letrozole observed in this study were the achievement of a lower number of mature follicles and a higher endometrial thickness as well as a similar pregnancy rate and a lower miscarriage rate compared with CC.

ICID 874414