Psychiatric disorders are more common in the mothers of children with autism spectrum disorder (ASD) or intellectual disability (ID) after the birth of their child. We aimed to assess the relationship between women’s psychiatric contacts and subsequent offspring with ASD/ID. We linked three Western Australian registers to investigate pre-existing maternal outpatient psychiatric contacts and the odds of ASD/ID in a subsequent child. Women with a previous outpatient psychiatric contact were more than twice as likely to have a child with ASD [OR 2.07 (95 % CI 1.7, 2.6)] or ID [OR 2.31 (2.1, 2.6)]. Further research exploring the effect on pregnancy outcomes of medications prescribed to women with psychiatric disorders is implicated.