Background:
Hypertension in pregnancy is an important cause of both maternal and fetal morbidity and mortality. Whether hypertension in pregnancy has its risk factor(s) in childhood is not known. The objective of this study was to examine the association between childhood risk factors and hypertension in pregnancy later in life.
Methods:
A nested case-control analysis was performed based on the longitudinal Bogalusa Heart Study cohort (67% white and 33% black), with an average follow-up period of 26.2 years. Cases were defined as women who had hypertension during pregnancy and had normal blood pressure measurements after the pregnancy (n=82). Controls were defined as women with normal blood pressure without hypertension in pregnancy (n=454). Childhood risk factors included body mass index (BMI), systolic and diastolic blood pressure, high- and low-density lipoprotein cholesterols, and triglycerides. Univariable and multivariable logistic regression were used to estimate the odds ratio (OR) and 95% confidence interval (CI), with childhood risk factors standardized to age- and race-specific z-scores based on the total population of 5419 female subjects.
Results:
Cases and controls had comparable age in childhood (10.1 vs 9.8 years, P=0.53). Cases vs controls had higher BMI (19.1 vs 17.6 kg/m2, P<0.001) and systolic blood pressure (101.8 vs 99.2 mm Hg, P=0.002) in childhood. In univariable analysis, significant childhood predictors for having hypertension in pregnancy included BMI (OR corresponding to 1 age- and race-specific standard deviation change =1.45, 95% CI: 1.15-1.83) and systolic blood pressure (1.48, 1.15-1.89). BMI and systolic blood pressure remained as significant predictors for having hypertension in pregnancy in multiple regression analysis (1.34, 1.03-1.75 and 1.33, 1.01-1.74, respectively).
Conclusions:
Childhood BMI and systolic blood pressure are significant predictors for having pregnancy-induced hypertension in adulthood, which underscores the importance of childhood risk factors assessment and early intervention.