The use of low-molecular-weight heparins in pregnancy--how safe are they?

Curr Opin Obstet Gynecol. 2007 Dec;19(6):573-7. doi: 10.1097/GCO.0b013e3282f10e33.

Abstract

Purpose of review: Low-molecular-weight heparins are in widespread use during pregnancy. As with every treatment in pregnant patients, concerns have been raised about the safety of Low-molecular-weight heparins. The purpose of the present article is to review recent advances, published during the past year, that have studied the maternal, fetal, and neonatal safety of Low-molecular-weight heparins in pregnant women.

Recent findings: Low-molecular-weight heparins do not increase the risk of maternal bleeding during pregnancy. Closed management is needed during the peripartum period, and discontinuing Low-molecular-weight heparins at least 12 h before delivery seems sufficient to prevent post-partum haemorrhage. The incidence of Low-molecular-weight heparins-induced immune reaction is low. Fondaparinux or danaparoid may be used as an alternative option in pregnant women with heparin-induced thrombocytopenia. Long-term Low-molecular-weight heparins therapy may be associated with osteopenia. Calcium vitamin D supplementation during pregnancy may reduce the risk of Low-molecular-weight heparins-induced osteoporosis. As Low-molecular-weight heparins do not cross the placenta, no fetal or neonatal complication has been reported. Beyond the safety question, Low-molecular-weight heparins have the potential to improve the live-birth rate in high-risk pregnancies (antiphospholipid syndrome, thrombophilia, or recurrent fetal loss).

Summary: Recent studies have confirmed the safety of Low-molecular-weight heparins therapy during pregnancy. The risk of potential side effects is low for both the mother and the neonate.

Publication types

  • Review

MeSH terms

  • Anticoagulants / adverse effects*
  • Anticoagulants / therapeutic use
  • Bone Density Conservation Agents / administration & dosage*
  • Bone Diseases, Metabolic / prevention & control
  • Calcium, Dietary / administration & dosage
  • Female
  • Heparin, Low-Molecular-Weight / adverse effects*
  • Heparin, Low-Molecular-Weight / therapeutic use
  • Humans
  • Postpartum Hemorrhage / prevention & control
  • Pregnancy
  • Pregnancy Complications, Hematologic / drug therapy*
  • Pregnancy Outcome
  • Risk Assessment
  • Safety
  • Thrombocytopenia / chemically induced
  • Thrombocytopenia / prevention & control
  • Thrombosis / prevention & control*
  • Vitamin D / administration & dosage

Substances

  • Anticoagulants
  • Bone Density Conservation Agents
  • Calcium, Dietary
  • Heparin, Low-Molecular-Weight
  • Vitamin D