CD40LG and congenital toxoplasmosis: This study aimed to describe seroprevalence in pregnant women in Catalonia using newborn dried blood samples (DBS) from the Catalonian Newborn Screening (NBS) Program; as well as to assess detection of Toxoplasma gondii antibodies in DBS (Anti-Toxoplasma gondii ELISA (IgG/IgM), Euroimmun Lubeck, Germany) as a NBS tool and for retrospective diagnosis of congenital toxoplasmosis (CT) in cases from the Spanish Research Network of Congenital Toxoplasmosis (REIV-TOXO).