Current views and opinions on pregnancy in diabetic mothers are presented. Special attention is paid to carbohydrate metabolism, pregestational diabetes mellitus (PGDM), gestational diabetes mellitus (GDM) and unclear heterogenous etiology of gestational diabetes mellitus (GDM). Suggestions for identification, diagnosis and treatment of GDM with an emphasis on early screening strategy are given. Obstetrical management and possible perinatal complications are discussed.