The purposes of the project are to determine the effects of abnormal glucose tolerance on outcome of the pregnancy, to determine long term prognosis for the women and their offspring, and to identify diabetes and impaired glucose tolerance during pregnancy in women in the Gila River Indian Community. By means of a glucose tolerance test as well as chart review, the diabetes status of women is determined at two-yearly intervals and during the third trimester of pregnancy. Offspring are followed from age 5 years and the effects of the diabetic intrauterine environment are evaluated in conjunction with other risk factors for obesity and diabetes. Between 1967-1976 and 1987-1996, the prevalence of diabetes has increased in Pima children aged at least 10 years. For example, in 10-14 year old boys it increased from 0 to 1.4% and in girls from 0.7% to 2.9%. A vicious cycle related to an increase in the frequency of exposure to diabetes in utero largely accounts for this epidemic of type 2 diabetes in children. The risk of diabetes in childhood and early adulthood is also related to low birth weight. Young Pima Indians with low birth weight were found to be insulin resistant compared with those with normal or high birth weight despite being less obese. Insulin resistance thus seems to underlie the high risk of early diabetes in Pima Indians with low birth weight.