Postpartum screening for persistent diabetes (T2D, maturity-onset diabetes of the young (MODY) or, less commonly, type 1 diabetes (T1D)) can occur immediately postpartum with either FPG or 24-h capillary blood glucose testing in those at high risk (increased BMI, high insulin dose in pregnancy and high-risk ethnicity). This evidence concerns the gene INS and type 1 diabetes mellitus.