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

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.