An Older Mum or Dad Increases Autism Risk
Byline: Jo Macfarlane MEDICAL CORRESPONDENT
COUPLES have a greater risk of having a child with autism if either the father or the mother is over the age of 35, according to a major international study.
The findings have come as a surprise as it was previously thought that delaying motherhood represented the greatest risk.
But the new study found that if either parent is between 35 and 39 - regardless of whether it is the mother or the father - then the extra risk of having an autistic child is the same.
In both cases there is a 27 per cent greater chance of having a child on the autistic spectrum compared with families where both parents are under 35. But if both parents are in their late 30s, the risk does not increase any further than if only one of them is.
However, if one parent is under 35 and the other 40 or over, the extra risk of autism is greater with an older mother (65 per cent) compared with an older father (44 per cent).
Autism was thought to be linked to natural changes that occur to both eggs and sperm as people age.
The new study suggests that while age still plays a role, there must also be some other explanation which is not yet known.
The researchers said that they 'could not rule out' the effect of other environmental factors such as infections, medication or fertility treatment, and added that more work was needed to see if this was the case.
But they also suggested their findings could reflect the fact that older parents may seek help for children with developmental delays sooner. …