Neonatal diabetes mellitus (NDM) is a type of diabetes. It happens during the first 6 months of human life. Infants with this condition do not produce enough insulin. This causes an increase of blood sugar. NDM is often mistaken for the much more common Type 1 diabetes, although type 1 often happens after the first 6 months of life. In almost 60% of those with NDM, this condition lasts their whole life.