Amino Acid and Acylcarnitine Profiles in Premature Neonates

Malnutrition is a common problem in the neonatal intensive care unit. Recent studies
indicate that prematurely born neonates commonly develop a severe nutritional deficit during
the first weeks after birth, referred to as extrauterine growth restriction. Despite an
increase in growth during the second month of hospitalization, many neonates are ultimately
discharged home having grown inadequately. The early nutritional deficit affects weight gain
as well as growth in length and head circumference. Aggressive administration of parenteral
amino acids to improve protein accretion rates in very preterm neonates has been supported
in the literature. Although tolerance of high dose amino acids has been described,
researchers acknowledge that sensitive tests to monitor amino acid toxicity are not readily
available in the clinical setting.

The goals of this study are:

- To better define normal amino acid and acylcarnitine values and how they change in
premature neonates

- To measure the effect nutritional support has (human breastmilk vs. formula) on amino
acid and acylcarnitines profiles

- To measure the effect of illness (parenteral nutrition associated cholestasis) on amino
acid and acylcarnitine profiles

- To better define abnormal metabolic profiles (low tyrosine levels) in neonates that
have hypothyroidism.