The authors investigated whether vascular complications of insulin-dependent diabetic pregnant women can influence on a long-term basis their children in adult life. In a group of 169 children of diabetic mothers (CDM) 12 developed diabetes during childhood and adolescence; in the remaining 157, age 20.75 +/- 0.31 (SE) the following tests were made: oral glucose tolerance test (OGTT), insulin level, parameters of the lipid metabolism, and blood pressure was assessed. CDM were divided into three groups: 1. CDM whose mothers had diabetic complications; according to White's classification of diabetes during pregnancy they belonged into class D and F (n = 10). 2. CDM whose mothers were classified with regard to diabetes during pregnancy as class B and C with subsequent toxaemia of pregnancy (n = 27), 3. CDM of mothers class B and C without toxaemia of pregnancy (n = 117). All investigated groups of CDM had significantly higher sums of blood sugar and insulin levels during the OGTT (P < 0.01), as compared with the control group (n = 31). In the first group of CDM the values were significantly higher than in the third group of CDM. As to cholesterol and triacylglycerol levels, the differences were not significant, the non-esterified fatty acid levels were higher in the second group than in controls (P < 0.05). In the first two groups also a higher systolic pressure was recorded than in controls (P < 0.01). Two children of the first group, two children of the second group and eight children of the third group of CDM developed diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)