Obese women 'could be increasing risk of having a child with autism'
Study findings 'may have serious public-health implications'
07:49 GMT, 9 April 2012
Obesity during pregnancy may increase chances for having a child with autism, provocative new research suggests.
It's among the first studies linking the two, and though it doesn't prove obesity causes autism, the authors say their results raise public health concerns because of the high level of obesity in this country.
Weighty issue: Obese women and those with Type 2 diabetes could be increasing their chances of having a child with a developmental disorder
Study women who were obese during pregnancy were about 67 percent more likely than normal-weight women to have autistic children. They also faced double the risk of having children with other developmental delays.
On average, women face a 1 in 88 chance of having a child with autism; the results suggest that obesity during pregnancy would increase that to a 1 in 53 chance, the authors said.
The study was released online today in Pediatrics.
Since more than one-third of U.S. women of child-bearing age are obese, the results are potentially worrisome and add yet another incentive for maintaining a normal weight, said researcher Paula Krakowiak, a study co-author from the University of California, Davis.
WHAT IS AUTISM
Autism refers to a range of related developmental disorders that start in childhood and affect the person for their whole life.
Symptoms can be split into three broad groups:
1) Problems with social interaction
2) Impaired language and communication skills
3) Unusual patterns of thought and behaviour
People with autism may also be over or under-sensitive to sounds, touch, taste, smells, light or colour.
Symptoms can range from mild to severe but all can cause anxiety.
While some people with autism can live relatively independent lives, others may need a lifetime of specialist support.
There is no cure but there are a number of treatments to help autistic people better cope with the world around them.
Around one in 100 children in the UK have autism spectrum disorder. It is three times more common among boys than girls.
For more information visit www.autism.org.uk
Previous research has linked obesity during pregnancy with stillbirths, preterm births and some birth defects.
Dr Daniel Coury, chief of developmental and behavioral pediatrics at Nationwide Children's Hospital in Columbus, Ohio, said the results 'raise quite a concern.'
He noted that U.S. autism rates have increased along with obesity rates and said the research suggests that may be more than a coincidence.
More research is needed to confirm the results. But if mothers' obesity is truly related to autism, it would be only one of many contributing factors, said Coury, who was not involved in the study.
Genetics has been linked to autism, and scientists are examining whether mothers' illnesses and use of certain medicines during pregnancy might also play a role.
The study involved about 1,000 California children, ages 2 to 5. Nearly 700 had autism or other developmental delays, and 315 did not have those problems.
Mothers were asked about their health. Medical records were available for more than half the women and confirmed their conditions. It's not clear how mothers' obesity might affect foetal development, but the authors offer some theories.
Obesity, generally about 35 pounds overweight, is linked with inflammation and sometimes elevated levels of blood sugar. Excess blood sugar and inflammation-related substances in a mother's blood may reach the foetus and damage the developing brain, Krakowiak said.
She added the findings 'may have serious public-health implications.'
The study lacks information on blood tests during pregnancy. There's also no information on women's diets and other habits during pregnancy that might have influenced fetal development.
There were no racial, ethnic, education or health insurance differences among mothers of autistic kids and those with unaffected children that might have influenced the results, the researchers said.
The National Institutes of Health helped pay for the study.
Dr Matthew Hobbs, head of research at Diabetes UK, said more research
was needed, adding: 'It is important to note that while it does show an association, it does not show that diabetes causes developmental problems.'