In recent years, new findings in the pathophysiology and treatment of diabetes mellitus during pregnancy and the development of improved fetal monitoring methods have considerably reduced the risk for mother and child. Given good metabolism the fertility of diabetics is comparable to that of nondiabetics. Perinatal mortality in centers is below 2%, and in 40% of the cases it is caused by congenital malformations. The incidence of malformations is 4-8%. Regulation of metabolism to near-normal values is vital for further improvement of mortality and morbidity rates, and should be aimed for prior to conception. In many cases insufficient attention is given to gestational diabetes. The risks accompanying untreated gestational diabetes are underestimated. In approx. 15% of such patients insulin therapy during pregnancy is necessary in addition to dietary measures. The goal of near normal metabolism (60-120 mg/dl, with mean daily values around 85-90 mg/dl) can usually be achieved during training, either prior to conception or at the latest during early pregnancy, by improved substitutional insulin therapy or insulin pump therapy. Short-term combined internalistic-obstetric follow-up at 14-day intervals ensures early prevention and detection of complications. The pregnancy can be continued to term in over 80% of cases, and spontaneous birth aimed for as the primary goal in the majority. With careful monitoring of metabolism, diabetics with no vascular complications may take low-dosage ovulation inhibitors to prevent conception. In isolated cases termination may be indicated in patients with severe vascular complications (proliferative retinopathy, severe nephropathy).