[Prevention of mother-to-child transmission of toxoplasmosis: perspectives].

In France, screening for toxoplasmosis is mandatory during pregnancy, whereas it is not performed in most other countries. The rationale for prenatal screening is to allow for several levels of intervention: primary prevention by health education; in case of seroconversion, prophylactic therapy; prenatal diagnosis using amniocentesis; the possibility of termination of pregnancy (TOP) in case of severe cerebral lesions at ultrasound; in most cases of fetal infection, antiparasitic therapy prenatally as well as postnatally. The French Health Authority (Haute Autorité de santé [HAS]) called into question the screening policy, but maintained it for 5 years pending randomized clinical trials. Recent data is available to answer some of the questions, but not the place of prenatal therapy. The sensitivity of prenatal diagnosis has progressed, while the place of TOP has decreased. The incidence of toxoplasmosis in the French population has fallen. Some studies have shown evidence in favor of prenatal therapy for infected fetuses. However, studies of prophylactic therapy are disappointing. These studies are purely observational and concern mostly spiramycine. For the first time, a multicenter randomized clinical trial of prevention of mother-to-child transmission of Toxoplasma gondii is underway (the TOXOGEST study). The HAS guidelines are that any suspected toxoplasmosis seroconversion should be confirmed in a reference laboratory, and that patients should be referred to expert centers without delay. It is not recommeded to start therapy before such expert consultation. The reference centers should provide counseling and access to prenatal diagnosis and therapy options.