Why is autism more common in twins?

Do twins have a higher chance of autism?

Several small studies conducted over the last three decades have found that it is much more common for identical twins to be diagnosed with autism than it is for fraternal twins.

Who is more likely to have a baby with autism?

Women over age 40 are 77% more likely than women under age 25 to have a child with autism. Women over age 40 are 51% more likely than women aged 25-29 to have a child with autism. Women aged 35-39 are 31% more likely than women aged 25-29 to have a child with autism.

Are twins more likely to have disabilities?

A number of studies have shown that, even among children of similar birth weight and gestational age, twins are more likely to suffer from the disorder.

Can one twin have Aspergers?

In identical twin sets where both children had some form of ASD, it was very unusual for one to have Asperger’s and the other to have autism or PDD-NOS. In other words, when one identical twin had Asperger’s, the other usually, did, too.

What can cause autism during pregnancy?

Studies have linked autism to a number of factors in pregnancy, among them the mother’s diet, the medicines she takes and her mental, immune and metabolic conditions, including preeclampsia (a form of high blood pressure) and gestational diabetes.

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What is autism caused by?

There is no known single cause for autism spectrum disorder, but it is generally accepted that it is caused by abnormalities in brain structure or function. Brain scans show differences in the shape and structure of the brain in children with autism compared to in neurotypical children.

Do twins have a higher risk of birth defects?

— Twins, triplets and other multiples have a nearly 50 percent greater chance of being born with birth defects, and boys tend to be more at risk than girls, according to two population-based studies conducted at the University of Florida.

What are the disadvantages of having twins?

With twins, you’re at greater risk for:

  • Premature birth. Twins are born prematurely more than half the time. …
  • Low birth weight (LBW). More than half of twins are born with LBW, weighing less than 5 1/2 pounds. …
  • Twin-twin transfusion syndrome (TTTS).

How common is autism in fraternal twins?

Based on data from 192 pairs of twins, the new study found a concordance rate for autism spectrum disorders of 77 percent among identical twin boys and 31 percent among fraternal twin boys.