- Neonates with a birth weight ≤2.5 kg and gestational age ≥38 weeks (indicating intrauterine growth retardation), gestational age < 35 weeks (premature infants), and/or chromosomal or recognizable phenotypic syndrome of non-cardiac congenital abnormalities associated with growth failure (e.g. Trisomy 21, Trisomy 13, Noonan's syndrome, Turner's syndrome) will be excluded from enrollment. Neonates who will not be placed on the high risk feeding protocol postoperatively will also be excluded.