Aromatase inhibitors, particularly letrozole, are now established as first-line ovulation induction agents, offering an effective ovarian stimulation strategy to enhance outcomes of intrauterine insemination. In recent years, they have also emerged as potentially valuable adjuvants to gonadotropin ovarian stimulation for IVF, particularly in fertility preservation in women with estrogen-responsive cancers. Their primary mechanism of action is to reduce circulating estrogen levels by inhibiting androgen aromatization. Recent studies have provided evidence that this property may confer therapeutic advantages in other patients undergoing IVF. In this article, evidence supporting the role of adjuvant letrozole in poor responders, as a moderator of OHSS symptoms, and an agent for improving the luteal phase after ovarian stimulation is reviewed. The use of letrozole for endometrial preparation in the frozen-thawed embryo transfer cycle is also considered.

中文翻译：

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来曲唑在 IVF 治疗中的作用：新疗法还是旧海市蜃楼？


芳香化酶抑制剂，尤其是来曲唑，现已被确定为一线排卵诱导剂，提供有效的卵巢刺激策略，以提高宫腔内人工授精的结局。近年来，它们也成为促性腺激素卵巢刺激 IVF 的潜在有价值的辅助手段，特别是在雌激素反应性癌症女性的生育力保持方面。它们的主要作用机制是通过抑制雄激素芳构化来降低循环雌激素水平。最近的研究提供证据表明，这种特性可能会为其他接受 IVF 的患者带来治疗优势。本文综述了支持辅助来曲唑在反应不良者中的作用、作为 OHSS 症状的调节剂以及改善卵巢刺激后黄体期的药物的证据。还考虑了在冻融胚胎移植周期中使用来曲唑进行子宫内膜准备。