The intellectual development of 33 children born to 33 diabetic Japanese mothers (ODM) was compared to that of 34 control offspring of non-diabetics delivered at Kurume University Hospital, Fukuoka, Japan, between 1987 and 1989. Intelligence scores on the Tanaka-Binet test were significantly lower in the ODMs at 3 years of age than in controls. Maternal age and infant IQ were inversely correlated in ODMs but not in controls. 
COMMENT. Infants of diabetic mothers may be at risk for impaired intellectual development, and especially infants born to older mothers. The difference in IQ between offspring of diabetics and non-diabetics was not associated with maternal toxemia or postnatal hyperbilirubinemia or hypoglycemia. A longer period of follow-up was considered important in determining the final cognitive outcome of these children.
Severe hypoglycemia and cognitive impairment in diabetes is reviewed and the link is considered not proven in a report from the Department of Psychology, University of Edinburgh, and Department of Diabetes, Royal Infirmary of Edinburgh . Among young adults with insulin dependent diabetes, recurrent episodes of severe hypoglycemia over a 5 to 15 year period have either a mild or negligible effect on cerebral function, except for a few subjects who are unusually vulnerable and suffer permanent brain damage. While strict glycemic control delays onset of retinopathy, nephropathy, and neuropathy, it is associated with a threefold increase in severe hypoglycemia.