Comparison of letrozole with continuous gonadotropins and clomiphene-gonadotropin combination for ovulation induction in 1387 PCOS women after clomiphene citrate failure: a randomized prospective clinical trial

Abstract

Purpose Letrozole, though reported to be an effective ovulation inducing agent, warrants larger randomized trials. The purpose of this study is to compare the efficacy of letrozole with that of rFSH and clomiphene citrate(CC)/rFSH for ovarian stimulation in IUI cycles. Methods Randomized, prospective, single-blinded clinical trial. 1387 PCOS women after CC failure were randomized into three groups: Group A received letrozole, Group B received CC with two doses rFSH and Group C received continuous rFSH day 2 onwards until hCG injection. Results Group A, B and C had an ovulation rate of 79.30%, 56.95% and 89.89% and cycle cancellation rate of 20.70%, 43.05% and 10.11%, respectively. Pregnancy rates in Group A, B and C were 23.39%, 14.35% and 17.92%, while the miscarriage rates were 13.80%, 16.67% and 14.52%, respectively. Conclusion Letrozole appears to be a suitable ovulation inducing agent in PCOS women with CC failure and is found to be most effective when baseline estradiol level >60 pg/ml.

A Clomiphene Citrate and Letrozol Varsus Tamoxifen and Letrozole as an Infertility Treatment in Women with Polycystic Ovary Syndrome

“…In recent years, the usefulness of letrozole for ovulation induction was investigated. A number of studies found that the effect of letrozole was comparable to that of combined CC and gonadotropins and of gonadotropins alone and CC alone for the induction of ovulation (Ganesh et al, 2009;Nejad et al, 2008). Also some studies have demonstrated that some patients do not respond to letrozole as an infertility treatment.…”

Glimpse on Splendid Aromatase Inhibitor – Letrozole - A Pragmatic Review

“…[4] However, studies have demonstrated that many anovulatory women are resistant to clomiphene citrate, failing to ovulate while utilizing the drug. [5,6,8] In patients resistant to clomiphene citrate, a common next step in treatment usually includes the use of injectable gonadotropins, with their risks of high order multiple pregnancies, ovarian hyperstimulation syndrome, painful injection sites, and demands extensive and invasive monitoring during treatment and higher cost of therapy. …”

“…The number of mature follicles at hCG administration was not commented upon. [5] It appears that letrozole, when used for clomiphene citrate resistant anovulatory women, confers higher pregnancy rates with lower miscarriage rates. This seems to occur even when the total number of mature follicles is lower than with clomiphene citrate.…”

Letrozole in ovulation induction (a review)

“…Эффективность летрозола сравнима с таковой при использовании рекомбинантного ФСГ для сти-муляции овуляции у женщин с СПКЯ, и, как было найдено, летрозол был подходящим и экономически рентабельным лекарственным средством для стиму-ляции [21].…”