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.