Chronic hypertension in pregnancy: are outcomes the same in patients on antihypertensives?*

Abstract

Objective To investigate differences in maternal and fetal outcomes among pregnant patients with chronic hypertension requiring antihypertensives for adequate control versus those who do not require antihypertensives. Study design Single-site retrospective cohort study including pregnant patients with chronic hypertension from 2015-2018. Two groups included those who required antihypertensives versus those who did not. Primary outcome is composite morbidity: pregnancy loss after 20 weeks, IUGR, maternal death, maternal stroke or TIA, pulmonary edema, renal failure, hypertensive emergency, HELLP syndrome, placental abruption or delivery before 34 weeks. Secondary outcomes included development of severe features, indication for preterm labor less than 37 weeks, incidence of severe range blood pressures, and neonatal outcomes. Student t, chi square, and Kruskal-Wallis tests where appropriate. Logistic regression used to account for potential confounders. Results Study cohort included 117 on antihypertensives and 114 not on antihypertensives. Use of antihypertensives was associated with the composite primary outcome (Odds ratio [OR], 3.88; 95% confidence interval [CI], 1.66–9.78). Use of antihypertensive medications was also associated with increased risk of prenatal diagnosis of IUGR, delivery prior to 34 weeks, development of severe features, severe blood pressure during pregnancy, earlier mean gestational age at delivery, lower mean birth weight, and higher risk of NICU admission. Logistic regression analysis showed that the association between medication requirement and our composite primary outcome persisted even after adjustment for age, BMI, and presence of gestational diabetes. Conclusion Our findings show an association between the requirement of antihypertensive medication use a significantly higher risk of composite primary outcome, prenatal diagnosis of IUGR, delivery prior to 34 weeks, and the development of severe features.