Rates of high blood pressure among pregnant women in the United States have risen sharply over the past several years, according to a report released last week by the Centers for Disease Control and Prevention (CDC). In 2024, approximately one in 10 pregnant women were reported to have hypertensive disorders during pregnancy, marking a 73 percent increase since 2016, when about one in 17 were affected.
The data, compiled by the CDC’s National Center for Health Statistics, were drawn from birth certificates completed by hospitals. These certificates include information on maternal health but do not capture chronic hypertension—high blood pressure diagnosed prior to pregnancy—which has also seen an increase and currently affects around 3.7 percent of pregnancies.
Hypertensive disorders during pregnancy are a significant concern as they contribute to complications such as preterm birth, low birth weight, stillbirth, placental abruption, and maternal organ failure. These conditions are among the leading causes of pregnancy-related mortality and morbidity in the United States, which has a higher maternal death rate compared with other high-income countries. Additionally, women who develop high blood pressure during pregnancy face an elevated lifelong risk of cardiovascular disease.
Experts note that the rising rates may partly reflect changes in clinical guidelines and screening practices. In 2018, the American College of Obstetricians and Gynecologists recommended earlier detection and improved management of hypertension in pregnancy. More recently, in 2023, the U.S. Preventive Services Task Force reaffirmed the importance of regular blood pressure monitoring in clinical care. “This is a substantial rise, and the author notes that this is probably underreported on birth certificates, so the true rates may be even higher,” said Dr. Elizabeth K. Cherot, an obstetrician-gynecologist and former CEO of the March of Dimes.
Beyond changes in diagnosis, underlying health trends may be contributing to the increase. The report highlights obesity as a critical factor, finding a strong correlation between higher pre-pregnancy body mass index (BMI) and the likelihood of developing hypertension during pregnancy. Additionally, increasing maternal age may play a role, as vascular stiffening associated with aging raises blood pressure risk. High blood pressure was most prevalent among pregnant women aged 40 and older.
The CDC report also reveals significant racial and ethnic disparities in the prevalence of hypertensive disorders. Rates were highest among non-Hispanic American Indian and Alaska Native mothers, reaching 13 percent, while non-Hispanic Asian mothers had the lowest prevalence at 7 percent. However, the rise in rates was observed across all racial and age groups and even among women classified as underweight, where the prevalence more than doubled from just under 3 percent in 2016 to over 5 percent in 2024. Pregnant Asian women experienced a doubling in hypertension prevalence despite having the lowest overall rates.
Researchers emphasize that the birth certificate data do not explain why these increases are occurring and call for further investigation into potential environmental and social factors driving this trend. Additional research will be necessary to better understand the underlying causes and to inform interventions aimed at reducing the growing burden of pregnancy-related hypertension.