What is the best working definition (operational threshold) of neonatal hypoglycaemia?

A blood glucose concentration of <2.6 mmol/L should be used as the definition (operational threshold) for neonatal hypoglycaemia. [Conditional recommendation]

There is some evidence for supporting the current operational threshold of <2.6mmol/L, and a lack of evidence to justify changing it.

Low certainty evidence from a single RCT shows that using a threshold of <2.0mmol/L has little to no effect on neurodevelopmental outcomes at 18 months but results in a large increase in moderate hypoglycaemia (2.0 – 2.6 mmol/L), and a moderate increase in severe hypoglycaemia (<2.0 mmol/L).

The effect on serious adverse effects was uncertain. The panel noted that babies with initial blood glucose concentrations <1.9 mmol/L were excluded from this trial, and that 18 months was likely too early to detect any effects of hypoglycaemia on neurodevelopmental outcomes of interest.

The operational threshold of blood glucose concentrations <2.6 mmol/L is consistent with WHO guidelines.

Consider additional investigations (see recommendation 18) and consultation with an paediatric endocrinologist or other relevant specialist if hypoglycaemia persists after 72 hours of age.

Blood glucose concentrations should continue to be monitored while babies are being treated for hypoglycaemia and for at least 12 hours after treatment stops and baby is feeding adequately.

Studies are needed on:

• Benefits and harm of changing to a lower or higher glucose threshold, particularly on later neurodevelopmental outcomes at least through to school age. 

The impact on health equity is not clear.