Randomized controlled trial comparing superovulation with letrozole versus recombinant follicle-stimulating hormone combined with intrauterine insemination for couples with unexplained infertility who had failed clomiphene citrate stimulation and intrauterine insemination.

OBJECTIVE

To compare the efficacy of letrozole to recombinant FSH for ovarian stimulation combined with IUI in a group of patients that had failed to conceive after clomiphene citrate (CC) and IUI.

DESIGN

Prospective randomized trial with human subjects.

SETTING

University-based fertility center.

PATIENT(S): Fifty couples with unexplained infertility that failed to conceive after three cycles of CC combined to IUI.

INTERVENTION(S): Couples were randomized to undergo superovulation either with letrozole or with recombinant FSH combined to IUI.

MAIN OUTCOME MEASURE(S): Clinical pregnancy per cycle of treatment and clinical pregnancy per couple.

RESULT(S): Pregnancy rate (PR) per cycle was 8.9% in the letrozole group as compared with 14% in the gonadotropin IUI group. This resulted in a cumulative PR per couple of 24% versus 36% and a take home baby rate of 20% versus 28%. Endometrial thickness was significantly lower in the letrozole group (7.1 +/- 2.3 vs 8.6 +/- 1.8).

CONCLUSION(S): Ovarian stimulation with letrozole is associated with acceptable PRs compared with gonadotropin with significant less cost, risks, and patient inconvenience.