A single centre, double arm, triple-blind randomised controlled trial
comparing the efficacy of combined letrozole and clomiphene versus the
only letrozole as a method of ovulation induction in women with
polycystic ovarian syndrome.
Objective: To evaluate the efficacy of combined therapy of letrozole and
CC compared to the use of letrozole alone to achieve ovulation in
infertile women with PCOS. Design: This was a single-centre, double arm,
triple-blind randomized controlled trial. The study was conducted after
taking approval from Institutional Ethics Committee and was
prospectively registered with the clinical trials registry- India.
Setting: Women were randomly assigned to receive a combination of 2.5 mg
letrozole and placebo daily or a combination of 2.5 mg letrozole and 50
mg CC daily on cycle days 3–7 for one treatment cycle. Methods: 80
participants were enrolled and randomized to either the letrozole-only
group (n=40) or the combined letrozole and CC group(n=40). Main outcome
measures: The primary outcome measure was documentation of ovulation,
confirmed by TVS 48 hours later with or without serum progesterone
estimation.Results: In comparison, both Intention to treat (ITT) and
per-protocol (PP) analysis showed a statistically significant increase
in ovulation rate in the arm treated with combined letrozole and CC.
Conclusion: Combination therapy with letrozole and clomipheneshould be
considered as a first-line ovulation induction agent for infertile
patients with PCOS owing to its low cost and better tolerability.
Additional well designed clinical trials are required to determine the
efficacy of the combination of letrozole and CC in terms of clinical
pregnancy rates and live birth rates. Funding: There is no funding
agency for this study. Keywords: Clomiphene, Letrozole, Polycystic
ovarian syndrome, ovulation induction