Chronic Hypertension During Pregnancy: Prevalence and Treatment in the United States, 2008-2021.

Background: Treatment of chronic hypertension during pregnancy has been shown to reduce the risk of adverse perinatal outcomes. In this study, we examined the prevalence and treatment of chronic hypertension during pregnancy and assessed changes in these outcomes following the release of the updated 2017 hypertension guidelines of the American College of Cardiology and American Heart Association.

Methods: We analyzed the Merative^TM Marketscan^® Research Database of United States commercial insurance claims from 2007 to 2021. We assessed the prevalence of chronic hypertension during pregnancy and oral antihypertensive medication use over time. We then performed interrupted time series analyses to evaluate changes in these outcomes.

Results: The prevalence of chronic hypertension steadily increased from 1.8% to 3.7% among 1 900 196 pregnancies between 2008 and 2021. Antihypertensive medication use among pregnant individuals with chronic hypertension was relatively stable (57%-60%) over the study period. The proportion of pregnant individuals with chronic hypertension treated with methyldopa or hydrochlorothiazide decreased (from 29% to 2% and from 11% to 5%, respectively), while the proportion treated with labetalol or nifedipine increased (from 19% to 42% and from 9% to 17%, respectively). The prevalence or treatment of chronic hypertension during pregnancy did not change following the 2017 American College of Cardiology and American Heart Association hypertension guidelines.

Conclusions: The prevalence of chronic hypertension during pregnancy doubled between 2008 and 2021 in a nationwide cohort of individuals with commercial insurance. Labetalol replaced methyldopa as the most commonly used antihypertensive during pregnancy. However, only about 60% of individuals with chronic hypertension in pregnancy were treated with antihypertensive medications.