Furthermore, a study21 stratified for maternal body mass index (BMI) (calculated as the weight in kilograms divided by height in meters squared) showed that the offspring of mothers with severe obesity with pregestational diabetes treated with insulin before and during pregnancy had a markedly increased risk of several psychiatric and mild neurodevelopmental disorders, whereas the presence of gestational diabetes did not markedly increase the risk for these disorders. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.