The risk for autism spectrum disorder (ASD) appears to be higher in children born after short or long interpregnancy intervals (IPIs), according to findings from the case-control Study to Explore Early Development (SEED). Specifically, ASD was more common among second- and later-born children who were conceived less than 18 months or at least 60 months after the mother's previous delivery. The correlation appeared to strengthen after a 60-month interval. IPI was not associated with other developmental disorders.

The risk for autism spectrum disorder (ASD) appears to be higher in children born after short or long interpregnancy intervals (IPIs), according to findings from the case-control Study to Explore Early Development (SEED).

Specifically, ASD was more common among second- and later-born children who were conceived less than 18 months or at least 60 months after the mother's previous delivery. The correlation appeared to strengthen after a 60-month interval. IPI was not associated with other developmental disorders.