We investigated the usefulness of a single value of maternal HbA1c in late pregnancy as a predictor for neonatal hypoglycaemia and secondly, to fi nd the appropriate threshold value. A prospective analysis of the HbA1c concentration between 36 to 38 weeks of gestation in 150 pregnant mothers with either pre-existing or gestational diabetes was performed. At delivery, glucose levels in the cord blood were analysed. Neonatal hypoglycaemia was defi ned as a blood sugar level of < 2.6 mmol/l. Receiver operator characteristic curve was constructed to evaluate the value of HbA1c concentration in predicting hypoglycaemia. There were 16 foetuses who were hypoglycaemic at delivery. The area under the ROC curve for predicting neonatal hypoglycaemia was 0.997 with a 95% confi dence interval of 0.992 to 1, a very good prediction rate. The optimal threshold value for HbA1c in predicting hypoglycaemia in the foetus was 6.8% (51 mmol/mol). HbA1c level in late pregnancy is a good predictor for hypoglycaemia in the newborn.