Autism Spectrum Disorder (ASD) comprises a range of developmental disorders diagnosed in early childhood, where their ability to communicate and interact are impaired. In the U.S., an estimated 1 in 59 children is born with ASD and the economic burden is a staggering $268 billion per year. Current therapies are post-symptomatic and include behavioral interventions or symptom-derived pharmacological treatments. Recently, the Van De Water group discovered that about a quarter of ASD cases are caused by maternal auto-antibodies that can hinder normal neurodevelopment in the fetus. Moreover, they elucidated the seven proteins targeted by these auto-antibodies in the fetal brain, including lactate dehydrogenase A and B (LDHA, LDHB) and stress-induced phosphoprotein 1 (STIP1). Herein, we aim to develop a System for Nanoparticle-based Autoantibody Retention and Entrapment (SNARE) prophylactic as a biomagnetic-trap for sequestration of disease-propagating Maternal Autoantibody-Related (MAR) autoantibodies. Our central hypothesis is that upon intravenous injection, the iron oxide NPs surface-conjugated with autoantigens will circulate throughout the maternal vasculature, and specifically ligate MAR auto-antibodies, thereby limiting antibody (Ab) transport across the placenta and preventing MAR autism.