Between 1970 and 2010, the rate of chronic hypertension among pregnant women rose from 0.11% to more than 1.5%, with advanced maternal age and year of delivery among the chief factors.
According to a study published in Hypertension, researchers also found a twofold higher prevalence of chronic hypertension in pregnant black women (1.24%) compared with their white counterparts (0.53%; RR = 2.31; 95% CI, 2.3-2.32).
“We found that mothers who were older when they became pregnant were more likely to have chronic hypertension,” Cande V. Ananth, PhD, MPH, chief of epidemiology and biostatistics at Rutgers Robert Wood Johnson Medical School, said in a press release. “Since more women are electing to postpone their first pregnancies, and advanced maternal age is strongly associated with chronic high BP, women should be aware of the risks associated with having high BP during pregnancy.”
During the study period, the overall prevalence of chronic maternal hypertension was 0.63%, rising from 0.11% in 1970 to 1.52% in 2010 (RR = 13.41; 95% CI, 13.22-13.61), the researchers wrote.
In other findings, overall hypertension prevalence in pregnant women increased by an average of 6% (95% CI, 5-6) per year. This annual rise was slightly higher among white women (7%; 95% CI, 6-7) compared with black women (4%; 95% CI, 3-4), according to the study.
Using the National Hospital Discharge Survey, which was discontinued in 2010, researchers analyzed the data of 151 million women (age range, 15 to 49 years; 62% white; 97% without diabetes) who underwent in-hospital delivery between 1970 and 2010.
“Women who already have high BP and are planning to become pregnant should work closely with their health care provider to closely monitor and manage their BP, especially during pregnancy, to reduce the serious health risks to both themselves and their unborn child,” Ananth said in the release.
“[The] study by Ananth et al provides a large sample of diverse, both racially and geographically, data suggesting a correlation between increasing maternal age and increasing maternal chronic hypertension within the U.S. and highlights prominent racial disparities between white and black women,” Dana M. Larsen, MD, and Jessica Sheehan Tangren, MD, MPH, nephrologists at Massachusetts General Hospital, wrote in a related editorial. “Many limitations exist in interpreting the outcomes of administrative data analyses used in this study. However, this study is an important step in trying to dissect the causes of this disparity. Trends in maternal age are likely to remain.” – by Scott Buzby
Disclosures: The authors, Larsen and Tangren report no relevant financial disclosures.