Cardiovascular Malformations Among Preterm Infants

This study showed that preterm infants have more than twice as many cardiovascular malformations as do infants born at term and that 16% of all infants with cardiovascular malformations are preterm. It also showed, not surprisingly, that there is an increased mortality rate among infants born preterm with a cardiovascular malformation. The additional effect of cardiovascular malformations on mortality rates is most marked for term and near-term infants, for whom mortality rates are otherwise low. The excess of cardiovascular malformations among preterm infants is intriguing but not easy to explain. Previous studies of birth weight among infants with cardiovascular malformations reported a significant increase in the likelihood of being small for gestational age among infants with tetralogy of Fallot, complete atrioventricular septal defect, hypoplastic left heart, or large ventricular septal defect. There is an obvious relationship between birth weight and gestational age, and those studies also showed an increased prevalence of prematurity among infants with tetralogy of Fallot, pulmonary stenosis, aortic stenosis, coarctation of the aorta, complete atrioventricular septal defect, or ventricular septal defect. There is also a high prevalence of cardiovascular malformations among late stillbirths, with major differences in the number and spectrum of cardiovascular malformations, compared with those seen in postnatal life. In particular, there is a greater incidence of coarctation of the aorta, double-inlet left ventricle, hypoplastic left heart, truncus arteriosus, double-outlet right ventricle, and atrioventricular septal defect among stillbirths. This spectrum of malformations is similar to that in our study and to those in other reports. Whether the increased prevalence of cardiovascular malformations among preterm infants and the increase in stillbirths suggest clues to the cause is difficult to say. The influence of preterm birth should be taken into account in risk assessment and risk stratification for surgical repair.