Mothers who are obese during pregnancy are more likely to have babies with autism, reveals US study.
The findings "appear to raise serious public health concerns," said the study in the journal Pediatrics, which comes amid an obesity epidemic in the United States with recent research showing autism strikes up to one in 88 children.
Researchers examined 1,004 mother-child pairs from diverse backgrounds in California -- about half of the children had autism, while 172 had other developmental problems and 315 were considered normal.
While the study did not say whether the mother's weight or diabetic status caused the children's developmental problems, it did find strong associations between the likelihood of such ailments and the mother's health in pregnancy.
For instance, mothers who were obese were about 67 percent more likely to have a child with autism and more than twice as likely to have a child with some kind of disorder than normal-weight moms without diabetes.
More than 20 percent of the mothers of children with autism or other developmental disability were obese. Just 14 percent of the mothers of normally developing children were obese at the time of pregnancy, it said.
Also, the autistic children of diabetic moms appeared to have more severe disabilities -- with greater deficits in language and communication skills -- than the autistic children of normal-weight moms.
"Over a third of US women in their childbearing years are obese and nearly one-tenth have gestational or type 2 diabetes during pregnancy," said lead author Paula Krakowiak, of the University of California, Davis.
"Our finding that these maternal conditions may be linked with neurodevelopmental problems in children raises concerns and therefore may have serious public health implications," she said.
Previous research has linked diabetes in pregnancy to development problems in children, but the association between autism and maternal diabetes has been inconsistent.
Scientists think that fetal problems may result from the prolonged exposure to high levels of insulin in diabetic moms, which requires greater oxygen use and may cut the necessary oxygen supply to the fetus.
Diabetes could also cut the needed levels of iron to the fetus, resulting in poor brain development.
According to Andrew Adesman, chief of developmental and behavioral pediatrics at Steven & Alexandra Cohen Children's Medical Center of New York, the study raises important questions but should not be interpreted as finding that metabolic disorders cause autism.
"Although other researchers are making headlines reporting advances in identifying genetic causes for autism, we must remember that environmental and other factors also likely play some role," said Adesman, who was not involved in the research.
"To the extent that there is an increase in diabetes and obesity in adults and likewise an increase of autism and related developmental disorders in young children, one cannot infer from this study that these metabolic conditions are the primary reason for the rapid increase in the incidence of autism."