Although major international guidelines recommend venous thromboembolism (VTE) prophylaxis during vaginal delivery hospitalization for women with additional risk factors, US guidelines recommend prophylaxis for a very small number of women who are at particularly high risk for an event. The purpose of this study was to characterize practice patterns of VTE prophylaxis in the United States during vaginal delivery hospitalizations and to determine VTE incidence in this population.

A population-level database was used to analyze VTE incidence and use of VTE prophylaxis during vaginal delivery hospitalizations in the United States between 2006 and 2012 (n = 2,673,986). We evaluated whether patients received either pharmacologic or mechanical prophylaxis. Hospital-level factors and patient characteristics were included in multivariable regression analysis that evaluated prophylaxis administration.

We identified 2,673,986 women who underwent vaginal delivery. Incidence of VTE increased during the study period from 15.6-29.8 events per 100,000 delivery hospitalizations. Within the cohort, 2.6% of patients (n = 68,835) received VTE prophylaxis. Pharmacologic prophylaxis was rare; <1% of women received unfractionated or low-molecular-weight heparin. Although patients with thrombophilia or a previous VTE event were likely to receive prophylaxis (60.8% and 72.8%, respectively), patients with risk factors for VTE such as obesity, smoking, and heart disease were unlikely to receive prophylaxis (rates of 5.9%, 3.3%, and 6.2%, respectively).

Our findings demonstrate that the administration of VTE prophylaxis outside a small group of women at extremely high risk for VTE is rare during vaginal delivery hospitalization. Given that VTE incidence is rising in this population, further research to determine whether broadening prophylaxis for VTE may reduce severe maternal morbidity and death is indicated.