In summary, our data showed that NBs exposed to T. gondii with LA IgG presented increased serum levels of specific IgM and IgG, exhibited more severe congenital toxoplasmosis symptoms, and had a 15-fold greater risk of developing toxoplasmosis than NBs exposed to T. gondii with HA, data not previously described in the literature. Here, CD40LG is linked to congenital toxoplasmosis.