Preterm delivery and later maternal cardiovascular disease risk

BACKGROUND: Women who have delivered a preterm infant are at elevated risk for cardiovascular disease (CVD), but mechanisms for this association are not understood. METHODS: In a cross-sectional study we investigated whether older women with a history of preterm birth (<37 weeks) had a higher prevalence of CVD. Participants were 446 women (mean age 80 years; 47% black) enrolled in the Pittsburgh, PA field center of The Health, Aging and Body Composition Study. Women reported preterm status, birth weight, smoking status, and selected complications for each pregnancy. CVD status was determined by self-report and hospital records. Analysis was limited to first births not explicitly complicated by hypertension or preeclampsia. RESULTS: Women who had delivered a preterm infant (on average 57 years in the past) had a higher prevalence of CVD. After adjustment for race, age, blood pressure, pulse wave velocity, interleukin-6, high-density lipoprotein cholesterol, and statin use, the odds ratio for CVD among women who delivered a preterm infant was 2.85 (95% confidence interval = 1.19-6.85) compared with women who had delivered term infants weighing more than 2500 g. This relationship was not altered by lifetime smoking history. There was evidence of negative confounding by statin use and high-density lipoprotein cholesterol. Among women delivering infants who were both preterm and low birth weight (<2500 g), the odds ratio was 3.31 (1.06-10.37) for CVD compared with women with term, normal weight infants. CONCLUSIONS: These results suggest that vascular and metabolic factors account for some but not all of the increased prevalence of CVD among women many years after a preterm birth.