Putting off having a child until later in life could increase the child's risk of developing autism. Increasing numbers of men and women are starting families later in life. Researchers from the University of California Davis looked at the records of all births in California between 1990 and the end of 1999 - a total of about 4.9 million births including 12,159 cases of autism. They found that a 40-year-old mother's risk of having an autistic child was 50% greater than that of a woman giving birth between the ages of 25 and 29. The father's age was only a factor when the mother was young. Fathers over 40 were twice as likey to have an autistic child if the mother was under 25 than fathers who were between 25 and 29. Some of the reasons put forward by the researchers to explain this were that sperm and egg quality declined with age and that environmental toxins accumulate in parent's bodies over time. But the risk of having a child with autism is still very low whatever age parents are.
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