Studies have shown a correlation between the levels of indoor and outdoor air pollution and the low birth weights. Among newborns in the regions of atmosphere soling was registered in 2.44 times more children with low weight. One can suppose that boys in the period of embryonic development were more vulnerable to atmosphere soiling. The proportion of newborn with low birth weight has increased from 3.46% to 6.55% in Charentsavan during the changes in the type of heating system. Moreover the number of newborn with good physical development decreased.