Type 2 diabetes in pregnancy: a growing concern

The prevalence of type 2 diabetes in children and adolescents is increasing, especially in populations with a very high overall prevalence of the disease.1 There is some evidence that diabetes in pregnancy might have a role in this increased prevalence. In a study of type 2 diabetes among Pima Indian children, the prevalence rose significantly between 1967 and 1996.18 This increase was felt to be due to an increase in weight seen in the children, as well as an increased frequency of exposure to diabetes in utero. In-utero exposure to diabetes is thought to lead to fetal hyperinsulinaemia, which causes an increase in fetal fat cells, leading to obesity and insulin resistance in childhood. These symptoms in turn lead to impaired glucose tolerance and diabetes in adulthood. Therefore, a cycle is set in motion of in-utero exposure to diabetes, leading to childhood obesity and glucose intolerance, and subsequently to diabetes in pregnancy. This sequence of events has not only be noted in Pima Indian children, but also in a more heterogeneous population in Chicago, USA, where children of mothers with diabetes were found to be more obese and have higher rates of impaired glucose tolerance than children of non-diabetic mothers.19