Thromboprophylaxis during Pregnancy and the Puerperium: Highlights from Current Guidelines

Venous thromboembolism (VTE) is one of the leading causes of maternal deaths worldwide. Mortality and morbidity of VTE are potentially preventable, since two-thirds of these women have identifiable risk factors and may benefit from appropriate thromboprophylaxis. Individual and careful assessment of the personal and family history as well as the assessment of preexisting and new-onset/transient risk factors during pregnancy and after delivery are mandatory for an effective prevention of VTE. Current guidelines (American College of Chest Physicians 2008, AWMF-Guideline 003/001 2009 and the Royal College Guideline No. 37 2009) provide practical recommendations for risk stratification regarding low, intermediate and high risk conditions. At high risk are women with previous VTE or thrombophilia. Corresponding to risk stratification grade C recommendations have been made for VTE prophylaxis during pregnancy and the puerperium. Prophylaxis with low molecular weight heparin (LMWH) should begin as early in pregnancy as practical. In women with lower risk mobilisation, avoidance of dehydration and mechanical methods (e. g., graduated compressive stockings) are sufficient. After delivery women with intermediate risk should be given LMWH for 7 days, women at high risk for 6 weeks or as long as additional risk factors are present. All women who have additional risk factors and who have had an elective Caesarean section should receive prophylactic LMWH for 7 days as should also all women who have had a Caesarean section in labour or an emergency Caesarean section. At the onset of labour, in case of any vaginal bleeding, prior to induction of labour or 12 h before an elective Caesarean section, antenatal LMWH prophylaxis should be discontinued, LMWH prophylaxis can be continued for 4-6 h after vaginal and for 6-12 h after Caesarean delivery when the women do not have an increased risk of haemorrhage. Current guidelines recommend than LMWH are the agents of choice for antenatal thromboprophylaxis; in comparison to unfractionated heparin, LMWH are associated with a substantially lower risk of heparin-induced thrombocytopenia and osteoporosis. Both oral anticoagulants and heparin are safe when breast-feeding.