Comparative study between effect of aromatase inhibitor and clomiphene citrate in gonadotrophin dose required for controlled ovarian stimulation in women with unexplained infertility

ABSTRACT

To compare the effects of aromatase inhibitor, letrozole and clomiphene citrate [CC] in gonadotrophin dose required for controlled ovarian stimulation [COS] in patients with unexplained infertility undergoing intra uterine insemination [IUI]. Non randomized prospective study. Al-Azhar University Hospital, Dammieta. Ninety patients with unexplained infertility undergoing COS and IUI. Thirty two women received letrozole in a dose of 2.5mg/day from day 3 to day 7 of the menstrual cycle + FSH, 18 women received CC in a dose of 100mg/day from day 3 to day 7 of the menstrual cycle + FSH and 40 women received FSH only as a control group. All patients were given highly purified FSH [75-150IU] starting of day 3 to day 7 until the day of hCG administration. Total FSH dose/cycle, number of mature ovarian follicles, estradiol [E2], lutenizing hormone [LH] levels, endometrial thickness, cervical mucus score at the day of hCG and pregnancy rate. The FSH dose was significantly lower in letrozole + FSH group and CC + FSH group when compared with FSH only group without a difference in number of follicles >/= l8mm. E2 levels were significantly lower in the letrozole + FSH group compared with the other two groups. Cervical mucus score, endometrial thickness and pregnancy rate were significantly lower in CC + FSH group when compared with the other two groups. Similar to CC, aromatase inhibition with letrozole reduces FSH dose required for COS without the undesirable anti-estrogenic effects sometimes seen with CC