BY BOB HOLT
A longer time between childbirths may lessen the younger child's chances of autism, according to an early study.
Children born less than two years after their siblings were considerably more likely to have an autism diagnosis compared to those born after at least three years, suggests the report, which is based on more than a half-million California children.
The effect was found for parents of all ages, decreasing the chance that it was older parents which caused the higher risk.
According to Reuters, of all second siblings whose mothers became pregnant with them less than a year after giving birth to the older sibling, about 7.5 in every 1,000 were diagnosed with autism. When mothers became pregnant three years or more after giving birth, about 2.5 out of every 1,000 younger siblings were diagnosed with autism.