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Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
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Evidence for functional immaturity of the ornithine-urea cycle in very-low-birth-weight infants

G Boehm1, D M Müller, K Beyreiss

  • 1Department of Pediatrics, Karl-Marx-University, Leipzig, GDR.

Biology of the Neonate
|January 1, 1988
PubMed

Insights

Preterm infants

Area of Science:

  • Neonatal nutrition
  • Pediatric metabolism
  • Infant physiology

Background:

  • Preterm infants have unique nutritional needs.
  • Assessing metabolic responses to protein is crucial for growth.
  • Immature renal function may affect protein metabolism.

Purpose of the Study:

  • To investigate the relationship between protein intake and serum urea/alpha-amino-nitrogen levels in preterm infants.
  • To compare the metabolic response to protein in very-low-birth-weight (VLBW) versus low-birth-weight (LBW) infants.
  • To determine the impact of postnatal age on protein metabolism in preterm neonates.

Main Methods:

  • Randomized, prospective study design.
  • Two groups of preterm infants (VLBW and LBW) with varying gestational ages.
  • Dietary protein intake adjusted (2.1–3.3 g/kg/day) using fresh or fortified human milk.
  • Serum urea and alpha-amino-nitrogen concentrations measured on postnatal days 8 and 21.

Main Results:

  • On day 8, VLBW infants showed no increase in serum urea with higher protein intake, unlike LBW infants.
  • A correlation between protein intake and serum alpha-amino-nitrogen was observed in VLBW infants on day 8.
  • By day 21, all infants demonstrated a correlation between protein intake and both serum urea and alpha-amino-nitrogen.
  • Findings suggest a limited capacity for urea production in immature preterm infants early in life.

Conclusions:

  • Immature preterm infants have a transiently limited ability to increase urea production in response to protein intake.
  • Postnatal maturation influences the infant's capacity to metabolize protein.
  • Metabolic responses to protein in preterm neonates should consider their developmental stage and immaturity.

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