Objective. To study the role of abnormal weight gain (AWG) during pregnancy as a risk factor for gestational diabetes mellitus (GDM), by performing a meta-analysis. Materials and methods. To solve the set problem, literature data from the leading bibliographic sources MEDLINE, Cochrane col., and EMBASE were analyzed. The WHO guidelines and the revised criteria of the Institute of Medicine (IOM, 2009) were used to estimate body mass index (BMI) and normal weight gain during pregnancy. The incidence of GDM was separately assessed for each of three groups of BMI indicators in terms of normal weight gain. The indicators were estimated by performing a meta-analysis using the Review Manager 5.3 (Cochrane col.). Results. 13 investigations meeting the search criteria were selected for analysis. A total of 85,559 pregnant women were examined. The odds ratio for a GDM risk in AWG for the normal BMI group was established to be 1.67 (95% CI, 1.28-2.18) (χ² = 32.1; p = 0.001), that for the baseline overweight group was 2.13 (95% CI, 1.47-3.11) (χ² = 24.9; p = 0.009), and that for the obesity group was 2.0 (95% CI, 1.53-2.63). Conclusion. AWG during pregnancy is an important factor in the development of GDM. The performed investigation allows pregnant women with AWG to be identified as a group at high risk for carbohydrate metabolic disturbances. Timely detecting AWG and more carefully following the balanced diet and exercise recommendations in such patients will be able to reduce the incidence of GDM and related perinatal complications.