Association of self-reported birth weight and preterm birth with blood pressure measures and risk for hypertension in older women from the women’s health initiative

Prenatal and early-life exposures may contribute to lifelong hypertension risk. We examined the relationships between an individual's birth weight or preterm birth status with their 1) risk for hypertension and 2) related quantitative blood pressure measures [mean systolic blood pressure (SBP), diastolic blood pressure (DBP), and 30-second pulse] among post-menopausal women from the Women's Health Initiative observational cohort. At study entry, birth weight and preterm birth status were self-reported by category (<6 lbs., 6-7 lbs. 15 oz., 8-9 lbs. 15 oz., or ≥10 lbs.; ≥4 weeks premature or full term). Prevalent and incident hypertension status were self-reported; baseline SBP, DBP, and 30-second pulse were measured by trained study staff. Linear, logistic, and Cox-proportional hazards regression models were used to estimate associations between birth weight and preterm birth and blood pressure outcomes. After adjustments, participants born weighing <6 lbs. had a higher mean SBP and were at increased risk for prevalent and incident hypertension compared to participants born at a normal birth weight (6-7 lbs. 15 oz.). Women born weighing ≥10 lbs. had a lower mean SBP and were at lower risk for prevalent and incident hypertension when compared to participants born at a normal birth weight. Compared to participants born full term, those born preterm were at increased risk for prevalent and incident hypertension; however, this relationship was weaker when stratifying by birth weight. Long-term follow-up or targeted counseling may be required for individuals born prematurely or at lower birth weights to prevent hypertension and associated cardiovascular outcomes.