Study: Autism risk rises in babies born soon after sibling

[Daandurreey]

could this explain the high autism rate in the Somali community?

 

By Liz Szabo, USA TODAY

 

Having babies close together appears to increase the risk of autism, a new study shows, and the more closely babies are spaced, the higher the risk that the younger one will be diagnosed with autism

The findings, published in today's Pediatrics, are the latest clue in doctors' efforts to unravel the mystery of autism and its causes. The disorder, which affects one in 110 American children, has baffled experts and sparked controversy for years.

 

Researchers say autism is a family of related disorders — probaby with different causes — that impair communication skills and social interaction.

 

In the study, children who were born less than one year after an older sibling were more than three times as likely to be diagnosed with autism, compared with children born at least three years after their mother's last pregnancy.Children born less than two years after an older brother or sister were almost twice as likely to be diagnosed with autism.

 

That's a "substantial" increase and "more than many of us would have thought," says Thomas Insel, director of the National Institute of Mental Health, who was not involved in the study. The National Institutes of Health, though, helped finance the study.

 

It's possible that pregnancy depletes mothers of vital nutrients, such as iron and folic acid, so that women have less to give their next baby, says study co-author Peter Bearman, a sociologist at New York's Columbia University. Closely spacing pregnancies also has been found to increase the risk of schizophrenia, premature birth, low birth weight and other conditions.

 

The new study, which involved more than 660,000 California children born between 1992 and 2002, adds to growing evidence suggesting that autism is related to events in early pregnancy, Insel says.

 

Researchers have identified a number of risk factors for autism. Children at higher risk include those born prematurely, those with older parents and those who develop congenital rubella syndrome, which can occur when a pregnant women contracts German measles, says Andrew Shih, vice president for scientific affairs at Autism Speaks, who described the new findings as "interesting and provocative."

 

Autism rates today are at least 10 times higher than they were just a couple of decades ago, Insel says. About 25% of that increase is the result of changes in the way the condition is diagnosed, Bearman says.

 

Genetics also appears to explain about 15% of cases, Insel says.

 

Scientists long ago dismissed vaccines as a cause of autism. One small but influential 1998 study in The Lancet, which launched a global vaccine-autism scare, has since been retracted and last week was labeled an "elaborate fraud" in an investigation in the British Medical Journal

 

The journal's editors wrote that the vaccine scare has diverted critical resources away from researching the real causes of autism, as well as studies of ways to help children and their families.

 

http://www.usatoday.com/yourlife/health/medical/autism/2011-01-10-autism10_st_N.htm?csp=34news

[Khayr]

Autism rates today are at least 10 times higher than they were just a couple of decades ago, Insel says

Doesn't this negate your premise - the high rate of autism in the somali community is caused by frequent births in the same families and minimal gaps between each birth in a family.