BACKGROUND Despite significant advances in our understanding of the pathophysiology of preeclampsia (PE), there are still many unknowns and controversies in the field. Women undergoing frozen-thawed embryo transfer (FET) to a hormonally prepared endometrium have been found to have an unexpected increased risk of PE compared to women who receive embryos in a natural FET cycle. The differences in risk have been hypothesized to be related to the absence or presence of a functioning corpus luteum (CL). OBJECTIVE AND RATIONALE To evaluate the literature on secretory products of the CL that could be essential for a healthy pregnancy and could reduce the risk of PE in the setting of FET. SEARCH METHODS For this review, pertinent studies were searched in PubMed/Medline (updated June 2020) using common keywords applied in the field of assisted reproductive technologies, CL physiology and preeclampsia. We also screened the complete list of references in recent publications in English (both animal and human studies) on the topics investigated. Given the design of this work as a narrative review, no formal criteria for study selection or appraisal were utilized. OUTCOMES The CL is a major source of multiple factors regulating reproduction. Progesterone, estradiol, relaxin and vasoactive and angiogenic substances produced by the CL have important roles in regulating its functional lifespan and are also secreted into the circulation to act remotely during early stages of pregnancy. Beyond the known actions of progesterone and estradiol on the uterus in early pregnancy, their metabolites have angiogenic properties that may optimize implantation and placentation. Serum levels of relaxin are almost undetectable in pregnant women without a CL, which precludes some maternal cardiovascular and renal adaptations to early pregnancy. We suggest that an imbalance in steroid hormones and their metabolites and polypeptides influencing early physiologic processes such as decidualization, implantation, angiogenesis and maternal haemodynamics could contribute to the increased PE risk among women undergoing programmed FET cycles. WIDER IMPLICATIONS A better understanding of the critical roles of the secretory products of the CL during early pregnancy holds the promise of improving the efficacy and safety of ART based on programmed FET cycles.

中文翻译：

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黄体分泌产物与先兆子痫

背景尽管我们对先兆子痫 (PE) 的病理生理学的理解取得了重大进展，但该领域仍有许多未知数和争议。与在自然 FET 周期中接受胚胎的女性相比，接受冷冻解冻胚胎移植 (FET) 到激素准备的子宫内膜的女性患 PE 的风险出乎意料地增加。已假设风险差异与功能性黄体 (CL) 的缺失或存在有关。目的和基本原理 评估关于 CL 分泌产物的文献，这些产物可能对健康妊娠至关重要，并可降低 FET 中 PE 的风险。搜索方法 对于本次审查，使用辅助生殖技术、CL 生理学和先兆子痫领域的常用关键词在 PubMed/Medline（2020 年 6 月更新）中搜索了相关研究。我们还筛选了最近英文出版物（动物和人类研究）中关于所调查主题的完整参考文献列表。鉴于这项工作的设计是叙述性审查，没有使用研究选择或评估的正式标准。结果 CL 是调节生殖的多种因素的主要来源。由 CL 产生的黄体酮、雌二醇、松弛素以及血管活性和血管生成物质在调节其功能寿命方面具有重要作用，并且在妊娠早期也被分泌到循环中远程发挥作用。除了已知的孕酮和雌二醇在妊娠早期对子宫的作用之外，它们的代谢物具有血管生成特性，可以优化植入和胎盘。在没有 CL 的孕妇中，血清松弛素水平几乎检测不到，这排除了一些母体心血管和肾脏对早期妊娠的适应。我们认为，影响早期生理过程（如蜕膜、植入、血管生成和母体血流动力学）的类固醇激素及其代谢物和多肽的不平衡可能导致接受程序性 FET 周期的女性的 PE 风险增加。更广泛的意义 更好地了解妊娠早期 CL 分泌产物的关键作用，有望提高基于程序 FET 周期的 ART 的疗效和安全性。