The Effect of Hypertensive Disorders of Pregnancy on Offspring Hypertension

Risk for hypertension in early adulthood is increased in children of mothers with chronic hypertension and further complicated in offspring exposed to hypertensive disorders of pregnancy (HDP) in gestation, according to study findings published in Hypertension.

Investigators sought to assess offspring from mothers who experienced HDP-affected pregnancies to determine the incidence of chronic hypertension and examine the effect of maternal chronic hypertension and HDP exposure in utero.

The investigators conducted a population-based cohort study using the Rochester Epidemiology Project medical records linkage system (links all medical records of providers in Olmsted County, Minnesota, US). The study included 8755 individuals with more than 1 year of follow-up born to 6658 unique mothers living in Olmsted County at the time of delivery from January 1976 through December 1982. Sufficient pregnancy records included at least 1 blood pressure reading to identify the possible presence of HDP. Diagnosis of HDP was attributed to either an HDP diagnostic code in medical records or at least 2 blood pressure measurements greater than 140/90 mm Hg.

Diagnostic codes in the Rochester Epidemiology Project were used to establish a diagnosis of chronic hypertension in mothers and offspring through December 2019.

A total of 655 offspring were born to mothers who experienced HDP during pregnancy. Among the 6658 unique mothers, 72.3% had 1 child in the cohort, 24.2% had 2 children in the cohort, and 3.5% had 3 or 4 children in the cohort (63 sets of twins total). Maternal age at delivery (26.7 years vs 26.9 years) showed no significant difference between mothers experiencing HDP vs those not experiencing HDP. Of the offspring born to mothers experiencing HDP, 48.7% were girls vs patients born to mothers not experiencing HDP, of which 48.1% were girls. Gestational age was at least 37 weeks for 91.8% of offspring born to mothers who experienced HDP vs 94.8% of offspring born to mothers who did not experience HDP.

The investigators found that significantly increased risk for chronic hypertension in offspring was independently associated with HDP exposure (hazard ratio [HR], 1.50; 95% CI, 1.18-1.90). Chronic hypertension in offspring was significantly higher among offspring of mothers with HDP vs mothers without HDP (8.9% vs 5.5% in offspring 30 years of age; 22.5% vs 15.7% in offspring 40 years of age).

Among offspring not exposed to HDP in gestation, maternal chronic hypertension associated with 1.6-fold increased risk for chronic hypertension.

Maternal chronic hypertension as a covariate was associated with increased risk for hypertension in offspring (HR, 1.73, 95% CI, 1.48-2.02).

Multivariate analysis including both risk factors maintained a significant association with increased risk (2.4-fold increase) of hypertension in offspring.

Study limitations include the use of diagnostic codes to identify chronic hypertension instead of blood pressure measurements, unaccounted-for change over time in the definition of hypertension, and unadjusted-for obesity as a confounding variable.

“Offspring of mothers with chronic hypertension are at increased risk of hypertension in early adulthood,” the study authors wrote. “Those who were exposed to hypertensive disorders of pregnancy in gestation are at additional increased risk and thus may benefit from additional screening and close clinical follow-up.”