Definition of neonatal hypoglycaemia: Is there a change?

Objective: To compare the definitions of neonatal hypoglycaemia in textbooks and among paediatricians in 1992 with those used in 1986. Methodology: A questionnaire was sent to 420 neonatal paediatricians in the UK and to 88 Australian neonatal paediatricians in 1992 asking for their definition of hypoglycaemia in term babies and preterm/small-for-gestational-age (SGA) babies. Fourteen textbooks on neonatal paediatrics (published since 1990) were also surveyed for the definition of hypoglycaemia used in the text. The UK paediatricians were also asked, 'Do you believe that a baby who is hypoglycaemic but has no abnormal clinical signs is at less risk of neurological damage than a baby who is hypoglycaemic with abnormal signs?' The 1992 results were compared with the published results of a similar survey in 1986. Results: There was a 68% response from neonatal paediatricians both in the UK and Australia. Similar to the 1986 results there continued in 1992 to be a wide range in the definition for hypoglycaemia (< 1-4 mmol/L) among neonatal paediatricians and in textbooks. The median of the definition of hypoglycaemia for both term and preterm/SGA babies among paediatricians and in textbooks in 1992 was significantly different from the results in 1986. Compared with 1986 there was a significant increase in 1992 in the number of paediatricians and textbooks defining a safe blood glucose concentration as being at least 2 mmol/L. Sixty per cent of UK neonatal paediatricians believe that a baby who is hypoglycaemic but has no abnormal clinical signs is at less risk of neurological damage than a baby who is hypoglycaemic with abnormal signs. Conclusions: From 1986 to 1992 there was a significant change in the definition of hypoglycaemia both among paediatricians and in neonatal textbooks compared with the definition in use during 1965-86. The findings suggest that neonatal paediatricians do change in their practice. The changes in the definition of hypoglycaemia may be due to the data available and discussion on hypoglycaemia since 1988. Neonatal paediatricians still attach significance to clinical signs associated with hypoglycaemia.