Gestational diabetes appears for the first time during pregnancy in a woman who has not previously been diagnosed with diabetes. It is caused by reduced sensitivity to insulin during pregnancy (insulin resistance), which leads to the hyperglycemia. The extra glucose can negatively affect the mother and the newborn. To minimize maternal and neonatal morbidity it is important to timely identify pregnant women with gestational diabetes. The method of choice is OGT testing, according to the criteria of HAPO study. Treatment for gestational diabetes aims to keep blood glucose levels equal to those of pregnant women who don't suffer from the disease. Treatment always includes diet based on a daily intake of 1800 kilocalories and appropriate physical activity. If diet and exercise are not sufficient to effectively control gestational diabetes insulin should be added to the therapy. The cooperation of the entire health team including midwives as their irreplaceable part is of utmost importance in the prevention, diagnosis and treatment of this disease.