UC Davis research study links age of mothers to risk for autism
Well, here is a very interesting study by researchers at UC Davis. Published today in the Febuary issue of the journal Austism Research -- advanced maternal age is linked to a significantly elevated risk of having a child with autism, regardless of the father's age according to an exhaustive study of ALL births in California during the period between 1990 and 1990 (4.9 million).
During this period there were 12, 159 confirmed cases of autism. The study found that the incremental risk of having a child with autism increased by 18 percent -- nearly 1/5th -- for every five year increase in the mother's age.
Get this: a 40 year old woman's risk of having a child later diagnosed with autism was 50 percent greater than that of a woman between the ages of 25 and 29 years old.
Get this: During the 1990's the number of California women over the age of 40 giving birth increased by more than 300 percent.
This is the same study that showed elevated rates of autism in affluent areas of Los Angeles -- mainly the westside. Perhaps one explanation is that women in the affluent areas on the west side of Los Angeles delayed having children due to professional careers.
I certainly have wondered over the years why there are so many well educated, affluent families, with autistic children. In addition to age as a factor, it is also possible that these families -- due to their education and access to excellent health care -- were able to detect early signs of atypical development.
What is so important about this study is the size of the sample. It is so rare that any research has access to so many typical births. More to be revealed.