System that categorizes diabetes mellitus in pregnancy. Class A-gestational diabetes with glucose intolerance occurring during pregnancy, may be managed with insulin or diet alone; class B-onset ? 20 years of age or < 10 yearsÕ duration, insulindependent; class C, onset at 10Ð19 years of age or 10Ð19 yearsÕ duration; class D-onset < 10 years of age, > 20 yearsÕ duration, or presence of hypertension or mild retinopathy; class F-renal disease; class H-coronary artery disease; class R-proliferative retinopathy; class T-after renal transplantation. (Class E is no longer used.)