Maternal infection with Toxoplasma gondii acquired during pregnancy occurs in more than 500 women per year in Switzerland. Systematic screening at the beginning of pregnancy allows the introduction of health education programs. The screening during pregnancy is performed to diagnose primary maternal infections and to propose prenatal diagnosis and treatment. The administration of specific antibiotherapy during pregnancy (spiramycine or the association of pyrimethamine and sulfonamides) significantly reduces the risk of fetal infection. Prenatal diagnosis of congenital toxoplasmosis is possible and reliable. It avoids unnecessary termination of pregnancy when the fetus is not infected and specific therapy in case of infection (association of pyrimethamine and sulfonamides). Prenatal treatment may be proposed without prenatal diagnosis as of the 16th week of gestation. In any case, prenatal treatment seems to reduce the incidence of severe congenital toxoplasmosis.