Prior preterm birth and maternal subclinical cardiovascular disease 4 to 12 years after pregnancy

We considered that women with prior preterm birth (PTB) would have evidence of subclinical atherosclerosis, endothelial dysfunction, and arterial stiffness.

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.

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.

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.