Extremes of foetal birthweight for gestation in infants of diabetic mothers

100 patients were registered at the Diabetic Clinic in 1981, where they were managed by a team of physician, obstetrician and paediatrician, based on a preset protocol. Only 92 patients were eventually analysed. The study showed a 1.3% incidence of pregnancies complicated by diabetes mellitus. The mean birthweights of infants of both gestational and established diabetics were heavier than that of the general population by race and gestation. 25% of the 92 infants of diabetic mothers have birthweight exceeding the 90th centile of population. Further division of the 92 patients into the "true gestational" diabetics, as shown by an oral glucose tolerance test performed 6 weeks post-natally, also showed a 25% incidence of macrosomia. Late antenatal booking, delayed detection of abnormal glucose tolerance and treatment attributed to the high incidence of macrosomia. Only one infant had birthweight below the tenth centile. There were no perinatal mortality in the 92 patients studied. Macrosomia is a common complication in infants of diabetic mothers despite a physician-obstetrician joint-care system. Also, the risk of having macrosomia amongst gestational diabetics is high.