Background: Women with preterm birth (PTB) have excess risk of cardiovascular disease (CVD) and metabolic dysregulation after delivery, but vascular mechanisms are poorly understood. We considered that women with PTB may have evidence of subclinical atherosclerosis after delivery, perhaps related to cardiometabolic risk factors. Materials and Methods: The Pregnancy Outcomes and Community Health Moms (POUCHmoms) study followed women from pregnancy through 7 to 15 years after delivery (n = 678). Women underwent B-mode ultrasound to measure the average intima-media thickness (IMT) across the common carotid, bulb, and internal carotid artery segments at follow-up (n = 605). Linear regression estimated the overall and segment-specific difference in IMT between women with preterm and term births. Results: Women were, on average, 38 years old (SD 5.7) at the follow-up visit. Those with a prior preterm versus term birth had thicker mean IMT (average of eight segments, 0.592 mm vs. 0.575, p = 0.04). Differences persisted after accounting for age, race, smoking, and body mass index (difference = +0.018 mm, p = 0.019) and were attenuated after adjustment for blood pressure, medication use, and total cholesterol (difference = +0.014, p = 0.052). Thicker mean bulb IMT in women with PTB was robust to cardiovascular risk factor adjustments (fully adjusted difference = +0.033, p = 0.029). Excluding cases of prepregnancy hypertension or preeclampsia did not change results. Conclusions: Mechanisms leading to subclinical atherosclerosis may link PTB with future CVD. PTB differences in maternal vessel remodeling in the carotid bulb, an arterial segment more prone to early development of atherosclerosis, were independent of traditional risk factors suggesting that novel processes may be involved.
Keywords: atherosclerosis; cardiometabolic risk factors; preterm birth.