Increased body weight and fat in the body causes alterations in hormone levels and this could cause some disturbance in the fetal environment. Earlier studies have also shown an association between gestational weight gain and elevated risk of developmental disabilities.
"Weight gain during pregnancy is not the cause of autism spectrum disorders, but rather may reflect an underlying process that it shares with autism spectrum disorders, such as abnormal hormone levels or inflammation," said Dr. Deborah Bilder, lead author of the study and an assistant professor of psychiatry at the U.
"Doctors have known for a long time that proper nutrition is essential to a healthy pregnancy. Rather, this study provides one more piece for the autism puzzle that researchers are exploring," she said.
"We hypothesize that excess pregnancy weight gain serves as a marker of gestational phenomena leading to autism spectrum disorders rather than as a direct risk factor," the study states. Even in genetically vulnerable offspring, the proposed underlying autism spectrum disorder etiology may be mediated by potentially modifiable factors."