​Summary: This study aimed to determine whether elevated blood pressure and stage 1 hypertension as newly defined by the 2017 American College of Cardiology and the American Heart Association guidelines are associated with an increased risk of hypertensive disorders of pregnancy and other adverse maternal and neonatal outcomes. In this retrospective cohort study, 18,801 women with singletons from 2013 to 2019 were categorized as normotensive, prehypertensive (elevated blood pressure), stage 1 hypertensive, or chronic hypertensive.

Findings: Of the 18,801 women, 13,478 (71.7%) were normotensive, 2,659 (14.1%) had elevated blood pressure, 1,384 (7.4%) were stage 1 hypertensive, and 1,280 (6.8%) were chronic hypertensive. A dose-response relationship was observed: the risk of hypertensive disorders of pregnancy increased from 4.2% in normotensive women to 6.7% in women with elevated blood pressure, to 10.9 in women with stage 1 hypertension, and 28.4% in women with chronic hypertension. Compared with normotensive women, women with stage 1 hypertension had an increased risk of neonatal intensive care unit admissions, preterm birth at <37 weeks’ gestation, and gestational diabetes.

The study demonstrates that elevated blood pressure and stage 1 hypertension, using the 2017 American College of Cardiology and the American Heart Association guideline definition, are associated with increased maternal and neonatal risk. This group of women warrants further investigation to determine whether pregnancy management can be altered to reduce maternal and neonatal morbidity.

This article references a study by UCLA Center for Health Policy Research's Associate Center Director Nadereh Pourat, Researcg Analyst Ana E. Martinez, and Senior Fellow Gerald Kominski.