Chronic hypertension during pregnancy doubled from 2007 to 2021

A study funded by the National Heart, Lung, and Blood Institute (NHLBI), a subset of the NIH, found that the prevalence of chronic hypertension in pregnancy doubled from 2007 to 2021. While the study did not focus on the causes behind this rise, the researchers hypothesize that rising maternal age, obesity rates, and other factors have contributed to this increase.

“These findings are deeply concerning because of the high rate of US maternal mortality, which is linked to chronic hypertension in pregnancy,” said study lead Stephanie Leonard, PhD, an epidemiologist at Stanford University School of Medicine in California, in the NIH press release. “Despite the availability of safe and effective treatments for chronic hypertension, the study speaks to an urgent need for improvement in care for this serious condition.”

Researchers published the data in Hypertension, a journal by the American Heart Association (AHA). According to the study, they analyzed data from the Merative Marketscan Research Database, which includes insurance claims across the US, isolating data on chronic hypertension in pregnancy and antihypertensive medication use.

Data found that, in 2008, 1.8% of pregnant individuals had chronic hypertension; that number increased to 3.7% by 2021. While the researchers considered the 2017 change in guidelines for diagnosing hypertension by the American College of Cardiology and AHA, they found that these changes did not skew prevalence for the studied period.

Despite the rising prevalence of chronic hypertension in pregnancy, they also noted that antihypertensive medication use in patients who needed the medication remained relatively stable, ranging from 57% to 60%. This data indicates that many patients who would benefit from these drugs did not receive them.

“We need to better understand gaps in treatment for chronic hypertension, especially in these high-risk groups,” said Candice A. Price, PhD, a program director at NHLBI, who specializes in women’s health research. “If we’re not detecting and treating chronic hypertension early, that’s a missed opportunity for protecting heart health during and after pregnancy.”