Inappropriately high plasma insulin levels in suspected perinatal asphyxia.

The aim of this study was to determine differences in levels of the major hormones responsible for glucose homeostasis (insulin and glucagon) in babies with acute neonatal encephalopathy secondary to perinatal asphyxia and to correlate these with outcome. In a prospective observational study, plasma insulin, C-peptide, glucagon and serum glucose levels were determined using standard techniques at specified times in term babies with a diagnosis on admission of perinatal asphyxia or acute neonatal encephalopathy. The setting comprised two university-affiliated, regional, tertiary level neonatal intensive care units. Thirty-one babies with a diagnosis of perinatal asphyxia or acute neonatal encephalopathy were entered into the study over 15 months and neurodevelopmental outcomes at 18 months of age for 28 babies were available for analysis. Babies with a poor neurodevelopmental outcome had significantly higher insulin and C-peptide levels than those who had a good outcome. Glucose delivery, serum glucose and glucagon levels did not differ significantly between the babies with a poor outcome and those with a good outcome. In conclusion, babies with significant foetal or neonatal asphyxia frequently have inappropriately high plasma insulin levels. This, either alone or in combination with other hormonal disturbances, may lead to the hypoglycaemia often associated with severe asphyxia and may predict a poor outcome.