A comparison of anastrozole and clomiphene citrate for ovulation induction in women with unexplained infertility undergoing intrauterine insemination

Objective: In order to overcome the undesirable effects of clomiphene citrate (CC) alternative regimens such as Aromatase inhibitors (AIs) have been recommended. Our objective was to compare the ovarian and endometrial effects of three day Anastrozole and clomiphene citrate in combination with gonadotropin in IUI cycles. Methodology: This was a prospective descriptive study in 55 infertile patients with unexplained infertility. The patients in Group A (29 patients) received CC and gonadotropin, in contrast to group B (26 patients) who received Anastrozole and gonadotropin. Primary outcome was the size and number of mature follicles together with endometrial thickness. Results: On the day of HCG administration Anastrozole group developed fewer mature follicles (0.54±0.64 vs. 1.07±1.06 P=0.032) and fewer total mature follicles (17 vs 31) compared with CC group, however the endometrial stripe thickness were similar in both group (7.73±2.54 vs. 7.89±1.93 P=0.800) Conclusions: Three day Anastrozole in addition to gonadotropin in IUI cycles develop fewer mature follicles significantly at the time of HCG- injection than those in C.C group, in unexplained infertility in IUI cycles. This dosage is equivalent to traditional CC dosage in IUI cycles on endometrial development.