Preterm birth and maternal smoking in pregnancy are strong risk factors for aortic narrowing in adolescence

Aim: Preterm transition from foetal to neonatal circulation might permanently alter aortic growth and development. To test this hypothesis, we measured aortic dimensions in adolescents born very preterm. Methods: Eighty-six healthy 15-year-old subjects were studied; 45 born very preterm at an average gestational age of 28 weeks (birth weight < 1500 g) and 41 controls born at term. Using a pulse-gated Fiesta sequence on a 1.5T MR-scanner, 25 images were collected within the heart cycle at several levels of the descending aorta. End-diastolic cross-sectional areas were semi-automatically calculated using an active contour model. Results: Subjects born preterm had narrower aortic lumen. The difference was 16% in the thoracic and 19% in the abdominal aorta after adjustment for body surface area and gender (p < 0.001). Maternal smoking in pregnancy was also found to be an independent risk factor for aortic narrowing in the offspring (difference 10%-13% throughout the aorta vs. offspring to nonsmoking mothers). Adolescents born preterm had higher systolic and diastolic blood pressures; however, blood pressures did not correlate with aortic size or maternal smoking during pregnancy. Conclusion: Very preterm birth and exposure to maternal smoking in foetal life are independent and strong risk factors for general aortic narrowing 15 years after birth.