Gestational diabetes mellitus (GD) is a widespread disease, the level of which continues to overgrow. Gestational diabetes mellitus significantly increases the risk of developing severe chronic pathology in both mother and child in the future. This publication is devoted to the prevention of GD during pregnancy, screening and diagnosis. Improve the course of pregnancy, childbirth, life for mother and child in women with GD, possibly with the earliest possible detection of disorders and complete correction of carbohydrate metabolism. To prevent GD development during pregnancy, it is necessary to identify risk factors, eliminate some of them, and prevent new ones. The risk factors for the disease include: overweight and obesity, pathological weight gain in the I–II trimester of pregnancy, burdened heredity, hypodynamics, old age, smoking, stress, polycystic ovarian syndrome, hypertension, hypothyroidism shortly before and/or during pregnancy, use of glucocorticosteroids, ethnicity, genetic factors. To prevent the development of GD in all women from early pregnancy, recommend nutrition; weight gain control; regular moderate physical activity; therapeutic exercise (in the absence of the threat of miscarriage, placenta previa and some other complications); limiting stressful situations; enough night's sleep; rational regime mode; abandonment of bad habits. This study has established the importance of early diagnosis and screening of pregnant women for GD. Diabetes mellitus is associated with increasing frequency of unfavourable pregnancy outcomes, perinatal morbidity and mortality. No conflict of interest was declared by the authors. Key words: diabetes mellitus, gestational diabetes, manifest, glucose.