James Andra H, Brancazio Leo R, Ortel Thomas L
Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC 27710, USA.
Clin Adv Hematol Oncol. 2005 Mar;3(3):187-97.
Normal pregnancy is accompanied by changes in coagulation that have likely evolved to protect women from the bleeding challenges of miscarriage and childbirth. Consequently, pregnant women are at an increased risk of thrombosis. The most important risk factors are thrombophilia and a history of thrombosis. Most thromboses in pregnancy occur in the left lower extremity, but pelvic vein thromboses are not uncommon. Thrombophilia increases not only the risk of maternal thrombosis but also the risk of poor pregnancy outcome. All pregnant women should be asked about a personal or family history of thrombosis and the details of their obstetrical history. Some women should undergo laboratory testing, particularly those with a personal history of thrombosis or a history of poor pregnancy outcome. The purpose of testing is to help determine which women should receive anticoagulation therapy, which is used not only to treat venous thromboembolism, but also to prevent thromboembolism and reduce the risk of poor pregnancy outcome in women with thrombophilia. Low-molecular-weight heparins are preferred over unfractionated heparin because they have a longer half-life and are presumed to have fewer side effects. Their longer half-life is a disadvantage around the time of delivery when unfractionated heparin, with its shorter half-life, is easier to manage. The risk of thrombosis is higher postpartum than during pregnancy, so anticoagulation therapy is usually continued for at least 6 weeks after delivery.
正常妊娠伴随着凝血功能的变化，这些变化可能是为了保护女性免受流产和分娩时出血的挑战而演变而来的。因此，孕妇发生血栓形成的风险增加。最重要的风险因素是血栓形成倾向和血栓形成病史。妊娠期间的大多数血栓形成发生在左下肢，但盆腔静脉血栓形成也并不少见。血栓形成倾向不仅增加了孕产妇血栓形成的风险，还增加了不良妊娠结局的风险。所有孕妇都应被询问个人或家族血栓形成病史以及产科病史的详细情况。一些女性应接受实验室检查，特别是那些有个人血栓形成病史或不良妊娠结局病史的女性。检查的目的是帮助确定哪些女性应接受抗凝治疗，抗凝治疗不仅用于治疗静脉血栓栓塞，还用于预防血栓栓塞并降低有血栓形成倾向女性发生不良妊娠结局的风险。低分子量肝素优于普通肝素，因为它们的半衰期更长，且推测副作用更少。在分娩时，它们较长的半衰期是一个不利因素，此时普通肝素半衰期较短，更易于管理。产后血栓形成的风险高于孕期，因此抗凝治疗通常在分娩后至少持续6周。
