This post is the second in a series about results from the EARLI study - a unique, long-term prospective study of prenatal autism spectrum disorder risk factors and markers. Launched in 2008, the EARLI study is one of the most extensive ongoing epidemiologic studies to understand the complex causes of autism.

The placenta is the temporary organ that controls the fetal environment and, despite this all-important role, has rarely been considered in studies of neurodevelopmental disabilities, including autism. An innovative study recently looked at the vascular networks of placentas from EARLI moms and compared them with those from a general population of births. Since autism appears to start in early fetal life, the placental functioning might influence risk for early developmental processes going awry.

EARLI researchers measured the placenta size, shape and depth and mapped out the thickness, length, and geometric locations of its veins and arteries. They discovered that placentas from EARLI mothers had lower transport efficiencies, which could affect the transport of nutrients, oxygen and other molecules to the fetus, when compared to the general population.

More research now needs to be done to determine if the vascular networks of placentas can be considered a biomarker of autism risk, and how they might be related to neurodevelopment of autism and other conditions.