Abstract

Introduction: Infertility is a multidimensional health problem with social & economic consequences. Female factor remains the foremost reason (40%-55%) and ovulatory disorders is the most common identifiable female factor. Ovulation induction is one of the most successful treatment of infertility due to anovulation.
Aim: To compare the effects of letrozole and clomiphene citrate (CC) for ovulation induction in women with anovulatory infertility.
Materials And Methods: In this assessor blind randomized controlled trial 80 infertile women with anovulatory infertility were randomized to receive either letrozole or CC for ovulation induction in incremental doses for a maximum of three cycles. Main outcomes studied were endometrial thickness, ovulation rate, pregnancy rate and rate of mono-follicular development. Both the groups were followed by ultrasound until the dominant follicle reached a diameter ≥18 mm, human chorionic gonadotropin (hCG) 10,000 IU was given, and timed intercourse was advised.
Results : The mean age, duration of infertility,  body mass index, and endocrine status in both the groups were similar at baseline. Ovulation occurred in 36 subjects (90.0%) in the letrozole group and 29 (72.5%) in the CC group, with a statistically significant difference between the two groups (P=0.045). Mono-follicular development was seen in 60.0% of ovulatory cycles in letrozole group compared to 22.5 % in clomiphene group (p=0.001).  Pregnancy was achieved in 37.5% women in letrozole group and 25.0% in clomiphene group (p=0.228).  There was no statistically significant difference in endometrial thickness between the two groups at the time of hCG administration (9.71±1.16mm vs. 9.6±1.03 mm with letrozole and clomiphene respectively (p = 0.648).
Conclusion: The effect of letrozole showed a better ovulation rate and monofollicular  development as compared with CC. Letrozole may have a role as a first-line treatment for anovulatory patients with anouvulatory infertility.