Hyperglycaemia and the very preterm baby.

Neonatal hyperglycaemia, as usually defined (a whole blood glucose of >7 mmol/L), is common in the first week of life in babies born more than 12 weeks early. However, a review of a cohort of all such births in the north of England suggests that significant glycosuria is uncommon, and that there is no threat of an osmotic diuresis until the urine contains 2% glucose (by which time the blood glucose level almost always exceeds 15 mmol/L). The current statistical or epidemiological definition of hyperglycaemia (derived from data on term babies) needs to be replaced, for clinical purposes, by a more operationally relevant definition.