Options for the pharmacotherapy of toxoplasmosis during pregnancy

Toxoplasmosis infection during pregnancy can cause stillbirths, severe mental retardations or ocular disorders that can also occur later in life and have a potential to relapse. As the disease is generally asymptomatic, diagnosis relies on serological tests. Primary prevention intends to prevent the infection of the fetus, while secondary prevention aims at reducing the severity of sequelae. Preventive attitudes regarding congenital toxoplasmosis differ according to countries. In Austria and France, a nationwide programme based on the screening of seronegative pregnant women and the treatment of all seroconversions has been implemented. The UK and Norway have rejected such a screening due to the lack of evidence of its efficacy. A review of published studies showed that no randomised controlled trials have been conducted. The only available data come from retrospective studies and are methodologically flawed. The impact of chemotherapy on primary and secondary prevention still needs to be assessed. This lack of evidence results in conflicting attitudes that increase the anxiety already raised in pregnant women and doctors by the occurrence of a maternal toxoplasmosis during pregnancy. Before making any change in preventative strategy, it is of utmost importance to increase our knowledge on treatment efficacy through proper randomised trials of existing drugs and of new potentially active compounds.