F Sohrabvand1, Sh Ansari, M Bagheri. 1. Department of Infertility & IVF, Vali-e-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran. fsohrabvand@yahoo.com
Abstract
BACKGROUND: Adding metformin to clomiphene citrate in clomiphene-resistant polycystic ovary syndrome (PCOS) patients increases ovulatory response. However, because of anti-estrogenic effects of clomiphene it may be associated with lower pregnancy rate, offsetting the ovulation rate benefit. Letrozole is an aromatase inhibitor which induces ovulation without anti-estrogenic effects. METHODS:Infertile women with PCOS were randomly divided into metformin-letrozole (29 patients) and metformin-clomiphene groups (30 patients). After an initial 6-8 weeks of metformin, they received either letrozole (2.5 mg) or clomiphene (100 mg) from day 3-7 of their menstrual cycle. Estradiol (E2) levels, number of follicles, pregnancy rates and endometrial thickness were measured on the day of HCG administration. RESULTS:Mean total E2 and E2 per mature follicle were significantly higher in clomiphene group without a difference in mean number of mature follicles >18 mm and ovulation rate. Endometrial thickness was significantly higher in letrozole group. The pregnancy rate in letrozole group (10 patients, 34.50%) as compared with clomiphene group (5 patients, 16.67%) did not show significant difference, whereas full-term pregnancies were higher in letrozole group [10 patients (34.50%) versus 3 patients (10%)]. CONCLUSION: In clomiphene-resistant PCOS patients, the combination of letrozole and metformin leads to higher full-term pregnancies.
RCT Entities:
BACKGROUND: Adding metformin to clomiphene citrate in clomiphene-resistant polycystic ovary syndrome (PCOS) patients increases ovulatory response. However, because of anti-estrogenic effects of clomiphene it may be associated with lower pregnancy rate, offsetting the ovulation rate benefit. Letrozole is an aromatase inhibitor which induces ovulation without anti-estrogenic effects. METHODS: Infertile women with PCOS were randomly divided into metformin-letrozole (29 patients) and metformin-clomiphene groups (30 patients). After an initial 6-8 weeks of metformin, they received either letrozole (2.5 mg) or clomiphene (100 mg) from day 3-7 of their menstrual cycle. Estradiol (E2) levels, number of follicles, pregnancy rates and endometrial thickness were measured on the day of HCG administration. RESULTS: Mean total E2 and E2 per mature follicle were significantly higher in clomiphene group without a difference in mean number of mature follicles >18 mm and ovulation rate. Endometrial thickness was significantly higher in letrozole group. The pregnancy rate in letrozole group (10 patients, 34.50%) as compared with clomiphene group (5 patients, 16.67%) did not show significant difference, whereas full-term pregnancies were higher in letrozole group [10 patients (34.50%) versus 3 patients (10%)]. CONCLUSION: In clomiphene-resistant PCOSpatients, the combination of letrozole and metformin leads to higher full-term pregnancies.
Authors: Antonio Requena; Julio Herrero; José Landeras; Esperanza Navarro; José L Neyro; Cristina Salvador; Rosa Tur; Justo Callejo; Miguel A Checa; Magí Farré; Juan J Espinós; Francesc Fábregues; María Graña-Barcia Journal: Hum Reprod Update Date: 2008-09-23 Impact factor: 15.610