We have used a simple affinity chromatography method to measure total glycosylated haemoglobins and glycosylated plasma proteins in maternal and cord blood at 50 normal deliveries. The affinity method gives equal weighting to glycosylated haemoglobins including haemoglobin F in cord blood. The mean values for glycosylated haemoglobins in maternal blood (6.49 +/- 1.2%) were significantly higher than those in cord blood (3.85 +/- 1.0%; p less than 0.001). The difference with glycosylated plasma proteins was less marked (maternal blood 5.61 +/- 0.9% and cord blood 4.75 +/- 0.6%; p less than 0.001). A contributory factor to these differences was the decrease in glucose concentration from 4.53 +/- 0.99 mmol/l in maternal blood to 3.59 +/- 0.8 mmol/l in cord blood. The results obtained at the birth of six children to diabetic mothers showed the same trends although the mean values for glycosylated haemoglobins (maternal blood 9.27 +/- 2.3%, cord blood 4.21 +/- 0.9%), glycosylated plasma proteins (maternal blood 7.44 +/- 1.6%, cord blood 5.45 +/- 1.7%) and glucose (maternal blood 10.22 +/- 7.3 mmol/l, cord blood 5.18 +/- 3.4 mmol/l) were higher in all samples than for the deliveries to non-diabetic mothers.