Blood Pressure Patterns and Subsequent Coronary Artery Calcification in Women Who Delivered Preterm Births

Women who delivered preterm infants have excess cardiovascular disease, but vascular pathways linking these conditions are not understood. We considered that higher blood pressure over 25 years among women with preterm delivery may be associated with coronary artery calcification (CAC). The CARDIA study enrolled 1,049 black and white women with births between 1985 and 2010 (n=272 ever preterm [<37 weeks]; n=777 all term births [≥37 weeks). Latent mixture modeling identified blood pressure trajectories across 20 years and these were related to CAC at years 20 and 25. Three systolic blood pressure (SBP) patterns were identified: low-stable (n=563, 53%), moderate (n=416, 40%), and moderate-increasing (n=70, 7%). Women with moderate-increasing SBP were more likely to have delivered preterm compared to those in the low-stable group (40% vs. 21%, p<0.0001) and they were more likely to have CAC (38.5% vs. 12.2%). The SBP and CAC association varied by preterm birth (p-interaction=0.04). Women with preterm delivery and a moderate-increasing SBP had a 2.17-fold higher hazards of CAC (95% CI 1.14, 4.12) compared to women with term births and a lower SBP pattern, adjusted for CVD risk factors and other pregnancy features. There was no excess CAC in women with moderate-increasing SBP and term births (adjusted HR 1.02 [0.49, 2.14). Associations were stronger in women with hypertensive disorders of pregnancy, but also detected in those with normotensive preterm deliveries. Women who deliver preterm infants are more likely to follow a high-risk blood pressure pattern throughout the childbearing years that is associated with CAC at midlife.