Prior Preterm Birth and Maternal Subclinical Cardiovascular Disease 4 to 12 Years After Pregnancy

Abstract

BACKGROUND: We considered that women with prior preterm birth (PTB) would have evidence of subclinical atherosclerosis, endothelial dysfunction, and arterial stiffness. METHODS: Four to 12 years after pregnancy, blood pressure and fasting lipids were analyzed, and women underwent evaluation, following standardized protocols, of carotid intima-media thickness (IMT), brachial flow-mediated dilation (FMD), and pulse wave velocity (PWV). Women with prior preterm (<37 weeks, n=181) or term births (>= 37 weeks, n=306) were compared. Those with preeclampsia or term small-for-gestational-age (SGA) births were excluded. RESULTS: Women with a prior preterm vs. term birth had higher blood pressure, on average, and a more atherogenic lipid profile. They also had marginally higher IMT (0.579 standard error [SE] 0.005-vs. 0.567 [0.004] mm, p=0.06), adjusted for body size, demographics, and smoking. IMT differences were greater among those with non-preeclamptic-indicated PTB (0.034 mm, p=0.05) and PTB<34 weeks (0.024 mm, p=0.04) compared to those with term births. These differences appeared to be explained in part by the atherogenic lipid elevations in women with preterm birth. Women with prior PTB<34 weeks tended to have lower FMD, but results were not statistically significant. PWV did not differ according to PTB. CONCLUSIONS: In the decade following pregnancy, women with non-preeclamptic-indicated PTB or PTB delivered before 34 weeks had higher blood pressure, atherogenic lipids, and IMT compared to women with term births. There may be subgroups of women with a prior PTB with excess cardiovascular risk that is detectable before overt clinical disease.