[Toxoplasmosis and pregnancy: current trends in serological follow-up].

Prevention of congenital toxoplasmosis is based on serological follow-up of pregnant patients. Routine serology includes search and titration of specific IgG and IgM. In presence of specific IgM, complementary tests should be carried out for a better dating of the contamination. Among them, the avidity test is the most currently used. It allows to exclude a recent infection in the majority of the cases. For difficult cases, it is useful to contact a specialized laboratory.