Women with excess weight or obesity face with pregnancy complications more often and have higher chances to give birth to a child with congenital defects. This was reported by Committee of public relationships of USA Teratological Society. According to the report women with excess weight suffer from sterility and such pregnancy complications as hypertension, cardiovascular diseases and insular diabetes more often. Fat women in childbirth are subjected to Cesarean section in majority of cases. The risk of malformation of children born by fat mothers is twice higher. Pathology of nervous system development is common for such children. In opinion of authors, women should start the struggle with excess weight before conception. At the same moment women sitting on a diet should avoid pregnancy because growing child needs full-value nutrition.