Preterm preeclampsia and thromboembolism risk in pregnant and postpartum patients

Abstract

Preterm preeclampsia (< 37 weeks) is associated with poor pregnancy and postpartum outcomes. Risk of thromboembolism in those delivered preterm with preeclampsia is unknown. We hypothesized that preterm preeclampsia is an independent risk factor for thromboembolic events in pregnant and postpartum patients. This is a retrospective cohort study using the National Inpatient Sample database from 2017-2019 from the HCUP. Patients who delivered preterm with preeclampsia were compared to those who delivered at term with preeclampsia and to those without preeclampsia. Exclusion criteria included those with a history of thrombophilia, antiphospholipid syndrome, or history of prior thromboembolism. The primary outcome was the rate of thromboembolism, including a composite of pulmonary embolism, deep vein thrombosis, and cerebral thrombosis/transient ischemic attack (TIA). Secondary outcomes evaluated the different types of thrombo-embolic event. Groups were compared via ANOVA, chi-squared, and logistic regression analysis. Characteristics that differed between groups with p-value < 0.05 were included in the regression. Of the individuals in the database, 48,862 (2.3%) met criteria for preterm preeclampsia. They were more likely to be older, identify as non-Hispanic black race, obese, diabetic, chronic hypertensive, and have lower household income (all p< 0.001) Of those with preterm preeclampsia, 0.4% experienced the primary outcome of any thromboembolic event, versus 0.1% of those with term preeclampsia and 0.1% of those without preeclampsia (p< 0.001). After controlling for possible confounders, preterm preeclampsia remained associated with any thromboembolic event (aOR 1.67, 95%CI 1.40-1.98), as well as the secondary outcomes of deep vein thrombosis (aOR 1.44, 95%CI 1.10-1.88) and cerebral thrombosis/transient ischemic attack (TIA) (aOR 2.02, 95% CI 1.55-2.63). Preterm preeclampsia is associated with an increased risk of any thromboembolic event, specifically deep vein thrombosis and cerebral thrombosis/TIA in pregnancy and the postpartum period.View Large Image Figure ViewerDownload Hi-res image Download (PPT)