Importance: Adverse perinatal circumstances have been associated with increased risk for autism in offspring. Women exposed to childhood abuse experience more adverse perinatal circumstances than women unexposed, but whether maternal abuse is associated with autism in offspring is unknown.

Objectives: To determine whether maternal exposure to childhood abuse is associated with risk for autism in offspring and whether possible increased risk is accounted for by a higher prevalence of adverse perinatal circumstances among abused women, including toxemia, low birth weight, gestational diabetes, previous induced abortion, intimate partner abuse, pregnancy length shorter than 37 weeks, selective serotonin reuptake inhibitor use, and alcohol use and smoking during pregnancy.

Design and setting: Nurses' Health Study II, a population-based longitudinal cohort of 116 430 women.

Participants: Nurses with data on maternal childhood abuse and child's autism status (97.0% were of white race/ethnicity). Controls were randomly selected from among children of women who did not report autism in offspring (participants included 451 mothers of children with autism and 52 498 mothers of children without autism).

Main outcome measures: Autism spectrum disorder in offspring, assessed by maternal report and validated with the Autism Diagnostic Interview-Revised in a subsample.

Results: Exposure to abuse was associated with increased risk for autism in children in a monotonically increasing fashion. The highest level of abuse was associated with the greatest prevalence of autism (1.8% vs 0.7% among women not abused, P = .005) and with the greatest risk for autism adjusted for demographic factors (risk ratio, 3.7; 95% CI, 2.3-5.8). All adverse perinatal circumstances except low birth weight were more prevalent among women abused in childhood. Adjusted for perinatal factors, the association of maternal childhood abuse with autism in offspring was slightly attenuated (risk ratio for highest level of abuse, 3.0; 95% CI, 1.9-4.8).

Conclusions and relevance: We identify an intergenerational association between maternal exposure to childhood abuse and risk for autism in the subsequent generation. Adverse perinatal circumstances accounted for only a small portion of this increased risk.