INTRODUCTION Pregnancy is one of the most important periods in a woman's life. A daily caloric increase of 150kcal throughout the first and 350kcal during the second and third trimesters is recommended. There are also increased requirements for some nutritive components. The aim of this study was to explore nutritive risk factors which affect hematological parameters and thus pregnancy and labor. It tested the hypothesis that there was a positive correlation between obese and underweight pregnant women and their nutrition, on one side, and hematological disorders of pregnant women on the other side. Material and methods The sample included 92 overweight, 65 underweight and 95 normally nourished pregnant women (control group). Blood analysis was compared with the results of the questionnaire on weekly consumption of different food groups. Results and discussion The incidence of anemia was very high in both nutritive risk groups, while the increased number of leukocytes was dominant in underweight pregnant women. Food questionnaire confirmed inadequate intake of nutritive components in risk groups. CONCLUSIONS All these facts may have important repercussions on pregnancy and labor, and anemia is often associated with prematurity, low birth-weight of infants, greater number of premature labors, as well as the increased perinatal mortality. This study has confirmed the hypothesis that well balanced nutrition is really very important for regular functioning of the whole body, especially in risk population such as pregnant women.