Autism risks detailed in children of older mothers

By LINDSEY TANNER, AP Medical Writer Lindsey Tanner, Ap Medical Writer – Mon Feb 8, 10:23 am ET

A woman's chance of having a child with autism increase substantially as she ages, but the risk may be less for older dads than previously suggested, a new study analyzing more than 5 million births found.

"Although fathers' age can contribute risk, the risk is overwhelmed by maternal age," said University of California at Davis researcher Janie Shelton, the study's lead author.

Mothers older than 40 were about 50 percent more likely to have a child with autism than those in their 20s; the risk for fathers older than 40 was 36 percent higher than for men in their 20s.

Even at that, the study suggests the risk of a woman over 40 having an autistic child was still less than 4 in 1,000, one expert noted.

The new research suggests the father's age appears to make the most difference with young mothers. Among children whose mothers were younger than 25, autism was twice as common when fathers were older than 40 than when dads were in their 20s.

The findings contrast with recent research that suggested the father's age played a bigger role than the mother's. Researchers and other autism experts said the new study is more convincing, partly because it's larger. Older mothers are known to face increased risks for having children with genetic disorders, and genes are thought to play a role in autism.

The study was released Monday in the February issue of the journal Autism Research.

Maureen Durkin, a University of Wisconsin researcher who also has studied the influence of parents' age on autism, said it's important to note that the increased risks are small and that most babies born to older mothers do not develop autism.

Durkin said the overall low risk for autism "may be the most important take-home message," especially for prospective parents

The study was based on records of all 5.6 million births in California between Jan. 1, 1990 and Dec. 31, 1999, and on cases of autism diagnosed before age 6. That number totaled more than 13,000; the study involved 12,159 autistic children for whom information on both parents' ages was also available.

The researchers took into account factors that might affect autism diagnosis, including parents' education and race.

Catherine Lord, director of the University of Michigan's Autism and Communication Disorders Center, said the study is stronger than previous research focusing on paternal age, and "gives us a fuller picture of what is going on."

Autism is a developmental disorder that involves mild to severe problems with behavior, communication and socializing.

Recent data suggest about 1 in 100 U.S. children are autistic, a rate that appears to have increased substantially in recent decades. Many experts believe that rise reflects better awareness and a broadening of the definition of autism rather than a true increase in affected children.

Births to older mothers also have risen in recent years, but that likely only accounts for a small part of the increase in cases, said study co-author and UC-Davis researcher Irva Hertz-Picciotto.

Dr. Edwin Cook, an autism researcher with University of Illinois at Chicago, offered a novel theory for why autism is more common among children with older parents: Autism is known to run in families and it may be that adults with mild or undiagnosed autism have children at later ages, Cook said.

The study doesn't include information on autism in adults.

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Doc Who Tied Vaccine to Autism Ruled Unethical

By EBEN HARRELL / LONDON Eben Harrell / London – 2 hrs 10 mins ago

In 1998, Andrew Wakefield, a gastroenterologist at London's Royal Free Hospital, published a study in the prestigious medical journal Lancet that linked the triple Measles, Mumps and Rubella (MMR) vaccine with autism and bowel disorders in children. The study - and Wakefield's subsequent public statements that parents should refuse the vaccines - sparked a public health panic that led vaccination rates in Britain to plunge.

Wakefield's study has since been discredited, and the MMR vaccine deemed to be safe. But now medical authorities in the U.K. have also ruled that the manner in which Wakefield carried out his research was unethical. In a ruling on Jan. 28, The General Medical Council, which registers and regulates doctors in the U.K., ruled that Wakefield acted "dishonestly and irresponsibly" during his research and with "callous disregard" for the children involved in his study. (See the year in health 2009.)

After the finding, Wakefield, who now heads an autism research center in Austin, Texas, described the decision as "unfounded and unjust." He added that he had "no regrets" over his work.

The General Medical Council, which will now decide whether to revoke Wakefield's medical license, highlighted several areas where Wakefield acted against the interest of the children involved in the 1998 study. It criticized Wakefield for carrying out invasive tests, such as colonoscopies and spinal taps, without due regard for how the children involved might be affected. It also cited Wakefield's method of gathering blood samples - he paid children at his son's birthday party $8 to give blood - and said that Wakefield displayed a "callous disregard for the distress and pain the children might suffer."

The panel also criticized Wakefield for failing to disclose that, while carrying out the research, he was being paid by lawyers acting for parents who believed their children had been harmed by the MMR jab.

The panel's ruling follows a refutation of Wakefield's research from the scientific community. Ten of 13 authors in the Lancet study have since renounced the study's conclusions. The Lancet has said it should not have published the study in the first place, and various other studies have failed to corroborate Wakefield's hypothesis. (Watch a video on the story of an uninsured woman.)

Despite this, the effects of the media frenzy surrounding Wakefield's research - a study found that MMR was the most written about science topic in the U.K. in 2002 - continue to be felt in Britain. Vaccination rates among toddlers plummeted from over 90% in the mid-1990s to below 70% in some places by 2003. Following this drop, Britain saw an increase in measles cases at a time when the disease had been all but eradicated in many developed countries. In 1998, there were just 56 cases of the disease in England and Wales; by 2008 there were 1,370.

Despite assurances from various health bodies that Wakefield's study was seriously flawed, he still has a dedicated following among parents concerned about a rise in autism rates in the U.K. and U.S. - the cause of which has so far baffled health experts. Wakefield is now the Executive Director of the Thoughtful House autism center in Texas, which the Times of London recently claimed receives millions of dollars in donations each year. At the ruling in London, Wakefield was flanked by a small group of supporters, some of whom shouted in protest as the ruling was read out. Speaking after the hearing, Wakefield remained unbowed, and addressed his supporters directly: "It remains finally for me to thank parents whose loyalty has been extraordinary, and I want to reassure them that the science will continue in earnest."

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