Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, Durham, USA; Division of Hematology, Department of Medicine, Duke University Medical Center, Durham, Durham, USA.
Departments of Medicine and Pathology & Molecular Medicine, Queen's University, Kingston, Ontario, Canada.
J Thromb Haemost. 2024 Feb;22(2):315-322. doi: 10.1016/j.jtha.2023.08.034. Epub 2023 Sep 13.
Women or people with a uterus are vulnerable to both normal and abnormal bleeding. During the reproductive years, the uterus is prepared physiologically to accept an embryo and support its growth and development during pregnancy, or in the absence of implantation of an embryo, recycle through the process of menstruation and accept an embryo a month or so later. If fertilization takes place and an embryo or embryos implant in the uterus, the fetal trophoblast, or outer cell layer of the embryo, invades and dilates the maternal spiral arteries and forms the placenta. No matter when in gestation a pregnancy ends, at the conclusion of pregnancy, the placenta should separate from the wall of the uterus and be expelled. Abnormal bleeding occurs during pregnancy or after delivery when the normal uteroplacental interface has not been established or is interrupted; during miscarriage; during ectopic pregnancy; during premature separation of the placenta; or during postpartum hemorrhage. Heavy menstrual bleeding, a subset of abnormal menstrual bleeding, can be quantitatively defined as >80 mL of blood loss per cycle. Unlike postpartum hemorrhage, heavy menstrual bleeding is significantly associated with an underlying bleeding disorder. While there is other reproductive tract bleeding in women, notably bleeding at the time of ovulation or with a life-threatening ruptured ectopic pregnancy, the unique bleeding that women experience is predominantly uterine in origin. Many of the unique aspects of uterine hemostasis, however, remain unknown.
女性或有子宫的人容易出现正常和异常出血。在生育期，子宫在生理上为接受胚胎和支持胚胎在妊娠期间的生长和发育做好准备，或者在胚胎没有着床的情况下，通过月经和一个月左右后接受胚胎的过程进行循环。如果受精发生并且胚胎或胚胎植入子宫，胎儿滋养层，即胚胎的外层细胞层，会侵入并扩张母体螺旋动脉并形成胎盘。无论妊娠何时结束，妊娠结束时，胎盘应与子宫壁分离并排出。异常出血发生在妊娠期间或分娩后，此时正常的胎盘子宫界面尚未建立或中断；在流产期间；在异位妊娠期间；在胎盘过早分离期间；或在产后出血期间。月经过多，即异常月经出血的一个子集，可以定量定义为每周期失血>80 毫升。与产后出血不同，月经过多与潜在的出血性疾病显著相关。虽然女性还有其他生殖道出血，尤其是排卵时出血或危及生命的宫外孕破裂时出血，但女性经历的独特出血主要来源于子宫。然而，许多子宫止血的独特方面仍然未知。
