ELSPAC (European Longitudinal Study of Pregnancy and Childhood) includes in Czech Republic the set of pregnant women who have their permanent address in Brno and Znojmo district with the term of the delivery between March 1991 and June 1992. Objective: Wide and repeated anamnestic and clinical investigations of parents and children making possible prospective analyses pregnancy and development of child. Design: Prospective study. Setting: Research Institute of Child Health, Brno.Methods: In the set of 7911 women, the relationship between subjective perception of weight and pregnancy in the first and second trimester was investigated. The data were obtained from two questionnaires filled by pregnant woman and obstetricians. Results: In the whole set, 12% of women are concerned with their weight intensively and percepti- on of their weight is rather negative. 5.8% of women show negative relationship to pregnancy at the beginning, in the second trimester it is only the small fragment of all women. The reason for the negative perception of the weight is influenced by somatic, psychic and social aspects. The most important issue is emotional stability. The most common increase in weight was between 8–15 kg, in average 11.34 kg. The increase in weight in pregnancy is, among other reason, media- ted by nutrition, smoking and job. Conclusion: Physical and psychical changes occur during the pregnancy. One of very evident changes is also increase in weight. The ability to accept this chance depends especially on emotio- nal stability, food, smoking and job of pregnant women.

        Key words: perception of body weight, increase in weight, perception of pregnancy