Diabetes sometimes appears for the first time during pregnancy. It is important that all cases are detected, so all pregnant woman should be screened for this condition. Screening protocols vary but usually involve urinalysis at all clinic visits plus a blood glucose test, taken after a meal, at 24-28 weeks. Risk factors include increasing maternal age (25 years upwards); obesity; family history of diabetes; and previous unexplained stillbirths or babies with congenital abnormalities. There is an increased frequency of gestational diabetes in Oriental women and those from the Indian subcontinent and the Middle East Once diagnosed, careful monitoring of diabetes is essential during pregnancy to minimise complications to mother and baby Mothers should be taught to monitor their own blood glucose levels. There is no place for urinalysis in the management of gestational diabetes mellitus. Advice from a dietitian is important and there should be easy access to a diabetes specialist nurse. The baby may be born large (macrosomia), with an increased risk of respiratory distress syndrome and hypoglycaemia. Hypocalcaemia and hyper-bilirubinaemia are other complications. Mothers may suffer birth trauma and require an assisted delivery because of the baby's large size. Although most women return to normal blood glucose levels in the puerperium, they are at considerably increased risk of developing non-insulin dependent diabetes mellitus in the following years. General education about recognising the symptoms of diabetes should be given, as well as advice about future pregnancies-including the need to seek preconceptual advice.