The MARBLES study investigates possible prenatal and post-partum biological and environmental exposures and risk factors that may contribute to the development of autism spectrum disorder (ASD). Women who already have a child diagnosed with an ASD and who are pregnant or planning an additional pregnancy have been recruited for the study, primarily through the California Department of Developmental Services in the United States of America. Over 500 pregnant women have been enrolled in the study. The study, which began baseline assessment in 2006, follows women from early in their pregnancy to when the child is 36 months of age. This includes weekly diaries, home visits and monthly assessments of the mother, child and sibling.

Recruitment is ongoing