High risk of second autistic child birth after a first

Researchers have warned that for parents who already have a child with Autism, there is a risk of almost 1/5 that their next child could also develop the disorder. This risk is higher than the previous estimates, and it is even higher if the next child is male. In families where more than one child suffers from Autism, the risk rises to 1/3 than any subsequent children will be affected.

The International study has been published in online in the Pediatrics Journal, and researchers studied 664 children in Israel, Canada and the US, is the largest study every into the risks of Autism recurring amongst siblings. This debilitating disorder affects a sufferer’s ability to socially interact and also communicate.

Previous estimates had the risk of a younger sibling developing the disorder as between 3-5%, but this new study has shown that the risk is substantially higher at around 18.7%. If the second child is a boy, that risk rises to over 26%, this is due to more boys than girls suffering from Autism; and if there are two older siblings with the disorder, the risk over 32%.

Sally Ozonoff, a professor at the MIND Institute at the California-Davis University in Sacramento led the study said that this had been the biggest study into sibling autism ever held, and none of the previous studies had ever identified that the risk of recurrence in siblings was so high.

Autism, which is also known as Autistic Spectrum Disorder, or ASD, is an umbrella term which covers many conditions such as Asperger’s Syndrome. These are all classed as developmental disorders and the ability to socially interact and communicate can be affected through the entire life of the sufferer. Around 1/100 children have some kinds of diagnosed Autism, and 80% of these are boys.

The average age of the 664 children that the researchers in Israel, Canada and the US studied was 8 months at the beginning, and they were tested for Autism once they reached 3 years. 132 of these met the criteria, and overall 26% of boys were diagnosed with ASD as opposed to 9% of girls, and the overall rate of ASD amongst those who were studied was 18.7%.

Those families who had one older child with Autism, or Simplex families, the rate of incidence rose to 20.1%. In those families where more than one child had Autism, the recurrence rate at 32.2%. Dr Ozonoff stressed that these were estimates that had been averaged across the families in the study, some families would have a risk factor of less that 18%, but some would invariable have more.