Background: Obstetric venous thromboembolism (VTE) is a leading cause of maternal morbidity and mortality. A clear understanding of the burden of VTE risk at a population level is a prerequisite to effective prevention; however, existing data are limited.
Objectives: Describe the prevalence and patterns of VTE risk factors among postpartum women and consider the implications for VTE prevention practices.
Method: We undertook a cross-sectional study of prospectively collected data from sequential postpartum VTE risk assessments completed between January 2015 and December 2017 in the Rotunda Hospital, Dublin.
Results: We analyzed postpartum VTE risk factors in a large unselected Irish urban obstetric cohort of 21 019 consecutively sampled women. This represents more than 90% of all women giving birth in a single institution over a 3-year period. The most common VTE risk factors related to maternal characteristics and delivery characteristics, including overweight and obesity (36%), age ≥35 (35%) and cesarean delivery (32%). More than three-quarters of women had at least 1 VTE risk factor (78%) and more than 40% had multiple (2 or more) VTE risk factors. One-fifth of women had no VTE risk factors before delivery, yet went on to develop VTE risk factors during delivery or in the postpartum period. Reflecting the differences in thromboprophylaxis thresholds internationally, the proportion of women who would have received a recommendation for postpartum thromboprophylaxis ranged from 7% to 37% under various clinical guidelines.
Conclusion: This study demonstrates the high prevalence of VTE risk factors among postpartum women. Postpartum VTE risk is highly individualized and complex.
Keywords: obstetrics; postpartum period; risk assessment; risk factors; venous thromboembolism.
© 2019 International Society on Thrombosis and Haemostasis.