In Reply We thank Lewandowski and Levy for their interest in our article.1 Several new studies identifying the adult cardiac phenotypes of moderate to extreme preterm birth have been published in the past few months, with more expected by the end of the year.1-3 Collectively, these studies greatly expand our knowledge of potential sequelae and suggest there may be multiple adult cardiac phenotypes after preterm birth. Although studies generally agree on findings of smaller biventricular chamber size, the effects of prematurity on mass and function are less consistent. Specifically, some studies report higher cardiac mass while others report lower mass.1-5 Even more surprising is that the same neonatal characteristics, such as birth weight, are associated with higher mass in some studies but lower mass in others.1,2,4 From a function standpoint, the right ventricle appears to be more affected than the left, although both reduced function and hypercontractile function have been reported.1-3,6