Rising maternal age raises autism risk

A 2012 meta-analysis of 25,687 autism cases finds that maternal age shows a monotonic, dose–response association with offspring autism: mothers ≥35 have an adjusted relative risk ≈1.31 compared with mothers 25–29, while mothers <20 show reduced risk (RR ≈0.76). The effect largely holds after controlling for paternal age and other confounders. — As populations delay childbearing, maternal-age–linked autism risk becomes a predictable factor for public‑health planning, reproductive counselling, and explanations of temporal autism trends.