OP11.04: Strong early impact of letrozole on ovulation induction outperforms clomiphene citrate in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) stands out as one of the most prevalent endocrinological issues leading to infertility in women globally. The primary challenge faced by these women is hyperandrogenism and/or chronic oligo/anovulation, ultimately resulting in infertility. This systematic review and meta-analysis seek to explore the efficacy of letrozole (LE), a relatively novel drug for ovulation induction (OI), by comparing it to the primary treatment modality for ovulation induction, clomiphene citrate (CC). A comprehensive literary search encompassed three databases and comprised randomised clinical trials comparing LE and CC for OI in women with PCOS. The diagnosis of PCOS adhered to the Rotterdam criteria. Data synthesis utilised a random-effects model. The search yielded a total of 1,994 articles, with 25 studies meeting inclusion criteria. In the LE group, endometrial thickness (ET) exhibited a significant increase (MD = 1.70, CI: 0.55-2.86; I2 = 97%, p-value = 0.008). Additionally, odds for ovulation (OR = 1.8, Cl: 1.21-2.69; I2 = 51%, p-value = 0.010) and pregnancy (OR = 1.96, CI: 1.37-2.81; I2 = 32%, p-value = 0.002) were markedly higher. The resistance index (RI) of subendometrial arteries exhibited a significant decrease (MD = -0.15, CI: -0.27- -0.04; I2 = 92%, p-value = 0.030). Women diagnosed with PCOS and treated with LE for OI demonstrated elevated rates of ovulation and pregnancy, along with increased ET. Additionally, the lower RI of subendometrial arteries may enhance intrauterine circulation, potentially creating more favourable conditions for embryo implantation and development. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.