An estimated 1 in 70 boys and 1 in 315 girls in the U.S. now have an autism spectrum disorder (ASD), according to a 2009 study by the Centers for Disease Control and Prevention. Increased awareness and detection as well as earlier diagnoses cannot alone account for the steep increase over the past few decades, experts say.
ON FIT PREGNANCY: Placenta Power
Autism is now widely believed to be caused by a combination of genetics and environmental factors. “Research indicates that even low-dose environmental exposures during pregnancy and early childhood have an effect on the developing brain,” said Linda S. Birnbaum, Ph.D., director of the National Institute of Environmental and Health Sciences, at a congressional hearing last August.
ON FIT PREGNANCY: Pregnant Belly Basics
The bodies of young children and fetuses are less able than those of adults to detoxify harmful substances and repair damage, and fetal exposure is of utmost concern, explains Santa Monica, Calif., pediatrician Harvey Karp, M.D. “The brain quadruples in size during the last trimester,” he says. “There are windows of vulnerability during this time where even miniscule amounts of chemicals could disturb development.”