NEWS YOU CAN USE: Child’s autism risk accelerates with mother’s age over 30.

The risk of having a child with ASD had a more complicated relationship to age in women than in men — whose risk of fathering a child with ASD increased linearly with age across their lifespan. Among women giving birth before the age of 30, the risk of ASD in the child showed no association with age — it was simply very low. But for babies born to mothers aged 30 and older, the chance of developing ASD rose rapidly with the mother’s age.

Lee noted that the non-linear maternal age effect that is relatively stronger than the paternal age effect on ASD risk has been observed in previous studies, but has not received much attention.