The endometrium is a multicellular tissue that is exquisitely responsive to the ovarian hormones. The local mechanisms of endometrial regulation to ensure optimal function are less well characterised. Transient physiological hypoxia has been proposed as a critical regulator of endometrial function. Herein, we review the literature on hypoxia in the non-pregnant endometrium. We discuss the pros and cons of animal models, human laboratory studies and novel in vivo imaging for the study of endometrial hypoxia. These research tools provide mounting evidence of a transient hypoxic episode in the menstrual endometrium and suggest that endometrial hypoxia may be present at the time of implantation. This local hypoxia may modify the inflammatory environment, influence vascular remodelling and modulate endometrial proliferation to optimise endometrial function. Finally, we review current knowledge of the impact of this hypoxia on endometrial pathologies, with a focus on abnormal uterine bleeding. Throughout the manuscript areas for future research are highlighted with the aim of concentrating research efforts to maximise future benefits for women and society.

中文翻译：

---

子宫内膜缺氧的存在及其作用

子宫内膜是一种多细胞组织，对卵巢激素反应灵敏。确保最佳功能的子宫内膜调节的局部机制尚不清楚。暂时性生理性缺氧已被认为是子宫内膜功能的关键调节因子。在此，我们回顾了有关非妊娠子宫内膜缺氧的文献。我们讨论了用于子宫内膜缺氧研究的动物模型、人体实验室研究和新颖的体内成像的利弊。这些研究工具提供了越来越多的证据表明月经子宫内膜出现短暂缺氧，并表明子宫内膜缺氧可能在着床时存在。这种局部缺氧可能会改变炎症环境，影响血管重塑并调节子宫内膜增殖以优化子宫内膜功能。最后，我们回顾了目前关于缺氧对子宫内膜病理影响的知识，重点是异常子宫出血。在整个手稿中，都强调了未来研究的领域，目的是集中研究努力，最大限度地提高妇女和社会的未来利益。