Inpatient pharmacological thromboprophylaxis in the antepartum period: an argument for risk-based thromboprophylaxis

Venous thromboembolism (VTE) is a significant cause of maternal morbidity and mortality in the United States. People hospitalized during pregnancy for reasons other than routine birth (ie, during antepartum admissions) are at increased risk of VTE compared with nonhospitalized obstetric patients, but there is no consensus regarding which patients should receive thromboprophylaxis during antepartum hospitalizations as the absolute event rates are low and anticoagulation can complicate antepartum management. We argue that an approach informed by individualized patient risk assessment is likely to produce the greatest net benefit for patients. Such an approach would avoid the pitfalls of universal pharmacologic prophylaxis (potential to interfere with unplanned delivery or receipt of neuraxial anesthesia) among patients for whom the absolute risk of VTE is low. In contrast, approaches that withhold pharmacologic prophylaxis from all antepartum patients likely place some at significant risk of VTE. We outline the arguments against universal pharmacologic thromboprophylaxis and against universal avoidance of pharmacologic thromboprophylaxis and discuss a risk-based approach proposed at our institution. Finally, we outline a research agenda for identification of optimal antepartum anticoagulation strategies.