Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark.
Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus, Denmark.
Semin Thromb Hemost. 2021 Oct;47(7):824-842. doi: 10.1055/s-0041-1726374. Epub 2021 Jun 15.
Low-molecular-weight heparin (LMWH) is commonly used for preventing or treating venous thromboembolic disease (VTE) during pregnancy. The physiological changes in maternal metabolism have led to discussions on optimal LMWH dosing strategy and possible need for monitoring. The aim of this systematic review is to summarize and discuss whether LMWH dose adjustment according to anti-Xa provides superior effectiveness and safety compared with weight adjusted or fixed dosed LMWH in pregnant women. A systematic literature search was performed in PubMed, Embase, and Scopus on September 26, 2020. The study is reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Effectiveness was defined as episodes of thrombosis and safety as bleeding episodes. In total, 33 studies were included: 4 randomized controlled studies and 29 cohort studies. Prophylactic dosing strategies employing weight dosed, fixed dosed, or anti-Xa adjusted LMWH dosing performed equal in effectiveness and safety. In pregnant women with VTE or high thromboembolic risk, therapeutic weight-adjusted LMWH and weight plus anti-Xa-adjusted LMWH provided equal results in terms of effectiveness and safety. Pregnant women with mechanical heart valves (MHVs) received therapeutic anti-Xa-adjusted LMWH with four out of seven studies presenting mean peak anti-Xa within target ranges. Still, pregnant women with MHV experienced both thrombosis and bleeding with anti-Xa in target. Based on the results of this systematic review, current evidence does not support the need for anti-Xa monitoring when using LMWH as thromboprophylaxis or treatment during pregnancy. Nonetheless, the need for anti-Xa monitoring in pregnant women with MHV may need further scrutiny.
低分子量肝素（LMWH）常用于预防或治疗妊娠期静脉血栓栓塞性疾病（VTE）。母体代谢的生理变化引发了关于 LMWH 最佳剂量策略和可能需要监测的讨论。本系统评价的目的是总结和讨论，与体重调整或固定剂量 LMWH 相比，根据抗 Xa 调整 LMWH 剂量是否在孕妇中具有更好的有效性和安全性。我们于 2020 年 9 月 26 日在 PubMed、Embase 和 Scopus 中进行了系统文献检索。本研究按照系统评价和荟萃分析的 Preferred Reporting Items（PRISMA）指南进行报告。有效性定义为血栓形成发作，安全性定义为出血发作。共纳入 33 项研究：4 项随机对照研究和 29 项队列研究。采用体重剂量、固定剂量或抗 Xa 调整的 LMWH 预防性剂量策略在有效性和安全性方面表现相同。在有 VTE 或高血栓栓塞风险的孕妇中，治疗性体重调整 LMWH 和体重加抗 Xa 调整 LMWH 在有效性和安全性方面结果相同。接受机械心脏瓣膜（MHV）的孕妇接受治疗性抗 Xa 调整的 LMWH，其中 7 项研究中有 4 项报告的平均峰值抗 Xa 在目标范围内。尽管如此，在目标范围内使用抗 Xa 时，孕妇仍会发生血栓形成和出血。基于本系统评价的结果，目前的证据不支持在使用 LMWH 进行血栓预防或治疗时进行抗 Xa 监测的必要性。然而，可能需要进一步研究 MHV 孕妇中抗 Xa 监测的必要性。
