Maternal obesity possibly linked to autism - Endocrine Today

Mothers who were obese were 67% more likely to have a child with autism spectrum disorder than normal-weight mothers without diabetes or hypertension. Obese mothers were also more than twice as likely to have a child with another developmental disorder, according to study results published online this week.

Paula Krakowiak, a PhD candidate in epidemiology at the University of California Davis MIND Institute, and colleagues included 1,004 mother/child pairs from diverse backgrounds enrolled in the Childhood Autism Risks from Genetics and the Environment (CHARGE) study. There were 517 children who had autism spectrum disorder (ASD); 172 who had other developmental disorders but not ASD; and 315 who were developing typically. The participants were enrolled between January 2003 and June 2010.

Story continues belowâ†"

ADVERTISEMENT

The researchers obtained demographic and medical information for the mothers and their children using the CHARGE Study Environmental Exposure Questionnaire, a telephone survey, the study participants’ birth files and medical records. The primary metabolic conditions of interest were type 2 diabetes or gestational diabetes, but the researchers also looked at hypertension.

Among children whose mothers were diabetic during their pregnancies, the study results indicated that the percentage of children with ASD born to women with type 2 diabetes or gestational diabetes (9.3%) or developmental disability (11.6%) was higher than the 6.4% of children with ASD born to women without these metabolic conditions. More than 20% of the mothers of children with ASD or developmental delay were obese vs. 14% of the mothers of typically developing children, the researchers said.

Approximately 20% of the children with ASD had mothers with a metabolic condition, and nearly 35% of the children with developmental delay had mothers with metabolic conditions. In contrast, 19% of the typically developing children had mothers with a metabolic condition.

The study also examined the link between hypertension and ASD or developmental disorders. The prevalence of high blood pressure was low for all groups, but more than two times higher among mothers of children with ASD or developmental delay than among mothers of children with typical development. However, the finding did not reach statistical significance.

The researchers reported that obesity is a significant risk factor for diabetes and hypertension and is characterized by increased insulin resistance and chronic inflammation, as are diabetes and hypertension. In pregnant women with diabetes, and possibility prediabetic pregnancies, poorly regulated maternal glucose can result in prolonged fetal exposure to elevated maternal glucose levels, which raises fetal insulin production resulting in chronic fetal exposure to high levels of insulin. Because elevated insulin production requires greater oxygen use, this may result in depleted oxygen supply for the fetus. Diabetes also may result in fetal iron deficiency. Both conditions can adversely affect fetal brain development, the researchers wrote.

“Over a third of US women in their childbearing years are obese, and nearly one-tenth have gestational or type 2 diabetes during pregnancy. Our finding that these maternal conditions may be linked with neurodevelopmental problems in children raises concerns and therefore may have serious public-health implications,” Krakowiak said in a press release. “While the study does not conclude that diabetes and obesity cause ASD and developmental delays, it suggests that fetal exposure to elevated glucose and maternal inflammation levels adversely affect fetal development.”

Disclosure: The study was supported by the National Institutes of Health, the US Environmental Protection Agency through the Science to Achieve Results (STAR) program, and the UC Davis MIND Institute.