Letrozole versus tamoxifen for ovulation induction in non-polycystic ovarian syndrome anovulatory infertile females

Abstract

Background: Anovulation is the most common cause for infertility, different oral agents are used for induction of ovulation, tamoxifen may be effective as letrozole in this era.Objective: The aim of this study was to compare the effectiveness of tamoxifen and letrozole in terms of ovulation induction outcomes in non PCOS anovulatory patients.Patients and Methods: This randomized single blinded clinical trial was conducted among a total of 120 patients with anovulatory infertility that were randomized to one of two treatment arms: Letrozole group and Tamoxifen group. The treatment was continued for three consecutive cycles. Main outcome measures were number of follicles ≥ 18mm, endometrial thickness and ovulation rate. Secondary outcomes measures were cumulative pregnancy rate and spontaneous abortion rates.Results: Mean number of mature of follicles ≥ 18 mm was statistically significantly higher in Tamoxifen group (1.9 ± 1.1) when compared to Letrozole group (1.5 ± 0.9) with p-value=0.03. Also, endometrial thickness was significantly different between both groups; as it was higher in Tamoxifen group (8.2 ± 1.6 mm versus 7.08 ± 2.4 mm) in Letrozole group (p-value=0.02). No significant difference was reported between both groups as regarding ovulation rate, pregnancy rate and spontaneous abortion rate, ovulation rate was 73.3% with Letrozole and 63.3% with Tamoxifen (P =0.3), cumulative pregnancy rate was 30% with Letrozole group and 23.3% with Tamoxifen group (p=0.5) and spontaneous abortion rate was 3.3% in Letrozole group and 5% in Tamoxifen group (p=0.9).Conclusion: Tamoxifen drug has comparable ovulation induction outcomes to letrozole with very low costs and side effects. Tamoxifen could be considered suitable for ovulation induction in developing countries