Necrotizing enterocolitis (NEC) is a serious gastrointestinal disorder that primarily affects preterm infants. About 10% of babies less than 32 weeks gestation at birth will develop it. Overall, 30% of babies who develop NEC will die from it, with many others developing long term gastrointestinal problems. The most important factor in its development is a premature intestinal tract. Epidermal growth factor (EGF) is an important growth factor in the development and maintenance of the gastrointestinal tract. This study will look for a relationship between EGF levels in premature babies and the development of NEC.