Autism linked to maternal obesity, diabetes

PUBLISHED : Tuesday, 10 April, 2012, 12:00am
UPDATED : Tuesday, 10 April, 2012, 12:00am


Young women, here's a compelling reason to lead a healthy lifestyle: do it for your future children's sake. Diabetic or obese mothers are more likely to have a child with autism or other neurodevelopmental disability, according to a major study published yesterday in the journal Pediatrics.

Researchers affiliated with the Medical Investigation of Neurodevelopmental Disorders (MIND) Institute at the University of California, Davis, found that obese mothers were 67 per cent more likely to have a child with autism as normal-weight mothers without diabetes or hypertension. Obese mothers were also more than twice as likely to have a child with another developmental disorder.

Diabetic mothers are nearly 21/3 more likely to have a child with developmental delays than healthy mothers. The proportion of diabetic mothers who had an autistic child was higher than in healthy mothers, but not statistically significant.

Among autistic children, those born to diabetic mothers had greater deficits in language comprehension and production, and adaptive communication, than those born to healthy mothers.

Even among non-autistic children, those born to diabetic mothers exhibited impairments in socialisation besides language comprehension and production compared with those born to healthy women.

The study surveyed 1,004 mother-child pairs (the children between two and five years old) from diverse backgrounds in California. There were 517 children who had autism; 172 with other developmental disorders; and 315 were developing normally.

The participants' demographic and medical information were obtained through a questionnaire, telephone survey and medical records. So what is the connection between metabolic conditions and brain development?

The study authors note that obesity is a significant risk factor for diabetes and hypertension, and is characterised by increased insulin resistance and chronic inflammation.

In diabetic - and possibility pre-diabetic - pregnancies, poorly regulated maternal glucose can result in prolonged fetal exposure to elevated maternal glucose levels, which raise fetal insulin production and result in chronic fetal exposure to high insulin levels.

Because high insulin production requires more oxygen use, this may result in depleted oxygen supply to the fetus. Diabetes may also result in fetal iron deficiency. Both can harm fetal brain development.

'The sequence of events related to poorly regulated maternal glucose levels is one potential biological mechanism that may play a role in adverse fetal development in the presence of maternal metabolic conditions,' says Paula Krakowiak, a biostatician affiliated with the MIND Institute.

According to a University of Hong Kong study in 1997, 5.49 children in every 10,000 in the city are diagnosed with autism spectrum disorder. Autism shows in poorer social interaction, communication deficits and repetitive behaviours, and often is accompanied by intellectual disability.