Association between insurance type and pregnancy outcomes in women diagnosed with hypertensive disorders of pregnancy

Objective: Hypertension in pregnancy is associated with adverse maternal and neonatal outcomes. Previous studies have demonstrated disparities in the risk of preeclampsia based on race, educational attainment, census tract income level and household income. Yet, data on the association of insurance type, classification of hypertension in pregnancy and outcomes have not been well described. We sought to compare outcomes in women with hypertensive disorders of pregnancy, by private versus public insurance. Study design: This was a retrospective cohort study of subjects with a hypertensive disorder of pregnancy that delivered >= 23-week gestation at Oregon Health & Science University (October 2013-December 2017). The cohort began with the 2013 American College of Obstetricians and Gynecologists Executive Summary on Hypertension in Pregnancy, which advised surveillance for severe features of disease in women with hypertension. Utilizing ICD-9 and ICD-10 discharge codes, followed by individual chart review, subjects were stratified into two groups by insurance status: Medicaid (public insurance), or individual or group health insurance (private insurance). As primary outcomes, we assessed severe features of preeclampsia, adverse maternal or neonatal outcomes (composite), and final hypertensive diagnosis: (i) chronic hypertension; (ii) gestational hypertension; (iii) preeclampsia without severe features and, (iv) preeclampsia with severe features. Differences in demographic and outcome data were analyzed by chi-square, t-test, and logistic regression. Results: Among 10 132 deliveries, 1335 (13.2%) were delivered with a hypertensive disorder of pregnancy. Medicaid covered 54.1% (722) of these deliveries; 44.1% (589) were covered by private insurance, and 1.8% (24) had unknown insurance. There was a similar percentage of subjects with Medicaid or private insurance in each hypertensive group (p = .08). However, compared to subjects with private insurance, those with Medicaid had more severe blood pressure (BP) elevations (systolic BP >= 160 mmHg, p = .001) and more cases of eclampsia (p = .04), while neonates of subjects with Medicaid had more intensive care unit admissions (p = .02), and preterm births (p < .001). The association between Medicaid insurance and severe BP elevation, or adverse neonatal outcomes, persisted after multivariable adjustment. Conclusion: Medicaid was not associated with a particular hypertensive disorder in pregnancy, yet those with Medicaid experienced more severe BP elevations and higher rates of adverse neonatal outcomes. More research is needed to understand potential risk factors and ways to improve outcomes for those with publicly funded insurance.