A randomized clinical trial study that compares 2 different timepoints to clamp the cord at birth. The study involves babies with heart disease born between 37 0/7- 41 6/7 weeks of pregnancy. Doctors will clamp the umbilical cord around 30 seconds (between 1-<60 seconds) after birth vs. around 120 seconds (between 60-<180 seconds) after birth. Doctors consider both treatment groups to be "usual care." A goal of this study is to find out which umbilical cord clamping timepoint is best for babies with heart disease.

The main reason for this research study is for researchers to evaluate the relationship between congenital heart disease and development. Currently, there is not enough long-term information available to researchers to predict a child's development if they have been diagnosed with Ductal Dependent Pulmonary Blood Flow (DDPBF), a type of congenital heart disease.