The air pollution contamination from the begin until the end of pregnancy can gives the negative impact against fetus growth. The air pollution, especially nitrogen dioxide from emission of motor vehicle smoke, can cause baby born under the standard weight.

David Q. Rich, ScD, MPH, the research leader from University of Medicine and Dentistry of New Jersey said that the relation between air pollution and fetus growth are strong.

The researchers observed 336.000 data from the newborn babies, who was born at the hospital, which collected from whole of the New Jersey nation between of 1999-2003. Those data then compared with result data from of the air pollution observation issued by Environmental Protection Agency.

The result is the women who pregnant and live around the worst air polluted area were born the baby with weight under the normal standard, than women who live in healthier environment.

Beside the air pollution factor, there are some others factor that effect the fetus growth in womb. They are education, income, the relation in a family, the healthy condition from the pregnant woman.