It is known that chronic hypertension and high BMI (body mass index) are risk factors for hypertensive disorders of pregnancy (HDP).  Studies documenting this risk have usually assessed blood pressure and BMI shortly before or early in pregnancy. The authors used data from the Coronary Artery Risk Development in Young Adults (CARDIA) study that followed subjects for 30 years.

For the CARDIA study 5115 Black and White men and women in four US cities (Birmingham, AL; Minneapolis, MN, Chicago, IL and Oakland, CA) were recruited in 1985 and followed until 2016. The mean baseline age was 24.1 years. Subjects included 2,787 women of whom 1,316 had pregnancies after the initial assessment. Four hundred sixty-eight women (47%) had been pregnant at least once prior to recruitment. Of these, 83 self-reported HDP and were excluded leaving a sample size of 1227 women - 48% Black and 53% White – of whom 53% had never been pregnant. 

Cardiovascular health was assessed using an American Heart Association scoring system called Life’s Essential 8 (LE8).  It uses eight indicators of cardiovascular health – diet, physical activity, nicotine exposure, BMI, blood lipids, blood glucose, blood pressure and sleep health to score cardiovascular health. Scores range from 0 to 100 with lower scores indicating worse cardiovascular health.  Subjects were seen at baseline, 2, 5, 7 and 10 years and then every 5 years through 2016.  At each assessment, women were asked about pregnancies and whether they developed HDP. 

At baseline and over the study period, women who developed HDP had lower overall LE8 scores.  When the data was controlled for age, race, years of education, household income, age at pregnancy, date of delivery and number of pregnancies, women who developed HDP also had lower individual LE8 scores for BMI, blood glucose, blood lipids and blood pressure. 

Over the 30 years of the study, LE8 scores decreased for all subjects but more so in those who had pregnancies complicated by HDP. 

Take home:  This study confirms that poor cardiovascular health prior to pregnancy increases the risk of developing HDP and a heart-healthy lifestyle prior to pregnancy may lower risk. The strengths of the investigation are the length of the study period and the fact that subjects were assessed prior to the pregnancies examined in the investigation.  The results strengthen the idea that optimizing cardiovascular health, particularly maternal weight and blood pressure, may decrease the risk of HDP.

Citation: Lower Pre-Pregnancy Cardiovascular Health is Associated with Hypertensive Disorders of Pregnancy. Dodds, LV et al.  Hypertension 2924 October 82(12):1696-1704.

About Research Roundup

Each quarter, our team of science writers reviews the most current research studies related to hypertensive disorders of pregnancy and summarizes those studies of greatest interest and potential impact to our community, including research studies related to risk assessment, diagnosis, prevention, and treatment. Special thanks to our volunteer research team including Dr. Sig-Linda Jacobson, Dr. Jennifer Mitchell, Dr. Julie Reynolds, Amanda Yang, and Simren Gupta who make Research Roundup possible, and to our Patient Advisory Council, who reviews these materials from the patient perspective.