Clomiphene citrate or letrozole as first-line ovulation induction drug in infertile PCOS women: A prospective randomized trial

OBJECTIVE: To compare Letrozole (5 mg) and clomiphene citrate (100 mg) as first line ovulation induction drug in infertile PCOS women. STUDY DESIGN: Prospective Randomised trial. SETTING: A Tertiary level infertility centre. Patients: 103 infertile PCOS women INTERVENTION(S): Treatment naïve infertile PCOS women were randomised to treatment with 5 mg letrozole (51 patients) or 100 mg clomiphene citrate (52 patients) daily starting day 2 to day 6 of menstrual cycle. Timed intercourse or Intra Uterine Insemination (IUI) was advised 24 to 36 hours after Human Chorionic Gonadotropin (HCG) injection. MAIN OUTCOME MEASURES: Ovulation rate, mono or multi follicular rate, days to ovulation, endometrial thickness, serum progesterone, serum estrogen, pregnancy rate, miscarriage rate. RESULTS: The mean age, Body Mass Index (BMI), duration of infertility in both Clomiphene Citrate (CC) and Letrozole groups were similar.Ovulation rate was 73.08% in letrozole group and 60.78% in CC, which was not statistically significant (P=0.398). There was no statistically significant difference between Endometrial thickness (CC 7.61 ±1.96, Let 7.65 ± 2.10), Sr E(2) on day of HCG (CC 178.3 ± 94.15, Let 162.09 ± 73.24), Days to ovulation (CC 14.2 ± 3.41; Let 13.13 ± 2.99) and Sr P(4) on D(21) (CC 10.58 ± 6.65; Let 11.86 ± 6.51). Monofolliculo genesis (CC 54.84, Let 79.49 %, P=0.027) and Pregnancy rate (CC 7.84%, Let 21.56% P=0.0125) were statistically significantly higher in letrozole group. CONCLUSION: Our study shows that letrozole has excellent pregnancy rates compared to clomiphene citrate. Letrozole should be considered at par with clomiphene citrate as first line drug for ovulation induction in infertile PCOS women.