In 1975 there was compelling evidence that glycaemic control in pregnancy was critical for a successful outcome for mother and baby. However, diabetic control could be monitored only by the women testing the urine for reducing substances. The renal threshold for glucose not uncommonly falls in pregnancy with resultant glycosia when the blood glucose values are still in the normal range. The instruction to diabetic pregnant women was to keep “the urine blue” (clinitest tablets were still in use and when five drops of urine and 10 drops of water were added to the clinic test tablet the mixture would remain blue if …