Preeclampsia linked to long-term venous thromboembolism risk during, after pregnancy

Key takeaways:

• Venous thromboembolism incidence was higher among those with vs. without a history of preeclampsia.
• Preeclampsia was also linked to increased deep vein thrombosis rate and pulmonary embolism.

Preeclampsia was associated with a significantly increased venous thromboembolism risk during pregnancy and beyond 6 weeks postpartum, according to an observational cohort study published in JAMA Network Open.

“The association between preeclampsia and the risk of venous thromboembolism during pregnancy and in the puerperium has been thoroughly examined, yet studies are conflicting,” Eva Havers-Borgersen, MD, PhD fellow in the department of cardiology at Copenhagen University Hospital – Rigshospitalet, Denmark, and colleagues wrote. “Some studies report an association between preeclampsia and an increased risk for venous thromboembolism during pregnancy and in the puerperium, while others report an association only in the puerperium but not during pregnancy or no association at all. Thus, much controversy still exists.”

Havers-Borgersen and colleagues conducted a cohort study evaluating data from 522,545 women (median age, 28 years) from Danish nationwide registries who were pregnant and gave birth from 1997 to 2016. All women were followed from pregnancy to incident venous thromboembolism (VTE), emigration, death or the end of the study period.

The primary outcome was incident VTE. Secondary outcomes included all-cause mortality.

Overall, 4.5% of women in the cohort had a preeclampsia diagnosis during pregnancy, and 0.9% of women developed VTE. Women with preeclampsia had a higher comorbidity burden compared with women without preeclampsia, including diabetes (3.4% vs. 1.5%) and inflammatory and autoimmune diseases (3.7% vs. 2%).

During a median follow-up of 10.2 years, preeclampsia diagnosis was associated with higher VTE incidence of 448.8 per 1,000 patient-years compared with 309.6 per 1,000 patient-years with no preeclampsia (adjusted HR = 1.43; 95% CI, 1.27-1.61). Researchers also observed an association between preeclampsia and increased deep vein thrombosis rate (aHR = 1.49; 95% CI, 1.31-1.7) and pulmonary embolism (aHR = 1.36; 95% CI, 1.08-1.73) when stratifying according to VTE subcategories.

These associations between preeclampsia and total VTE were prominent during pregnancy (aHR = 2.23; 95% CI, 1.98-2.52), during the first 6 weeks postpartum (aHR = 1.46; 95% CI, 1.28-1.65) and beyond 6 weeks postpartum (aHR = 1.35; 95% CI, 1.17-1.55).

“As women with preeclampsia also have been identified as being at increased long-term risk of other cardiovascular outcomes, this finding stresses the importance of increased attention and further research in prevention and treatment of preeclampsia,” the researchers wrote.