The survey article highlights the fact that the prevalence of gestational diabetes mellitus is steadily rising all over the world. Hyperglycemia, including that during pregnancy, is a powerful factor of endothelial damage, which may be responsible for the high rate of obstetric complications in gestational diabetes mellitus (threatened miscarriage, preeclampsia, placental insufficiency). The total impact of hormonal changes during pregnancy is characterized by insulin resistance and frequently decreased glucose uptake by insulin-sensitive tissues. Magnesium, one of the most important micronutrients, is of particular importance in maintaining the body's metabolic functions and in preventing obesity, hyperinsulinemia, and insulin resistance. At the same time, there is magnesium metabolic disturbance and undiagnosed hypomagnesemia in diabetes mellitus. On the basis of the data available in the literature, it is believed that magnesium deficiency, along with lifestyle and eating behavior, in pregnant women plays a large role in the development of gestational diabetes mellitus. When deficiency of magnesium is detected, its bioorganic salts with high bioavailability (Magne B6) are indicated as prevention of gestational diabetes mellitus and as part of combination treatment for already developed disease in pregnant women.