This study evaluated the association between prenatal depression and offspring autism-related traits. The sample comprised 33 prenatal/pediatric cohorts participating in the Environmental influences on Child Health Outcomes program who contributed information on prenatal depression and autism-related traits. Autism-related traits were assessed continuously and at the diagnostic cut-off using the Social Responsiveness Scale for children up to 12 years of age. Main analyses included 3994 parent-child pairs with prenatal depression diagnoses data; secondary analyses included 1730 parent-child pairs with depression severity data. After confounder adjustment, we observed an increase in autism-related traits among children of individuals with prenatal depression compared to those without (adjusted β = 1.31 95% CI: 0.65, 1.98). Analyses stratified by child sex documented a similar significant association among boys (aβ = 1.34 95%CI: 0.36, 2.32) and girls (aβ = 1.26 95% CI: 0.37, 2.15). Prenatal depression was also associated with increased odds of moderate to severe autism-related traits (adjusted odds ratio: 1.64, 95%CI: 1.09, 2.46), the screening threshold considered high risk of autism spectrum disorder (ASD) diagnosis. Findings highlight the importance of prenatal depression screening and preventive interventions for children of pregnant individuals with depression to support healthy development. Future research is needed to clarify whether these findings reflect overlap in genetic risk for depression and ASD-related traits or another mechanism.