Toxoplasmosis infection is caused by a parasite, Toxoplasma gondii. Eating raw or insufficiently cooked meat, not washing hands thoroughly after handling raw meat or gardening, or contact with cats' faeces (directly or indirectly through the soil, or possibly contaminated raw vegetables or fruits) can cause infection. Usually it is asymptomatic and self-limited. If pregnant women have not previously been exposed to the parasite and developed antibodies (immunoglobulins) while pregnant, the infection can be transmitted from the mother to the fetus (congenital toxoplasmosis). This is rare but has potentially serious effects of malformation, mental retardation, deafness and blindness of the infected infant, intrauterine death or stillbirth. The probability of infection is greater during the third trimester but the risk of the fetus developing major clinical signs is greater earlier in pregnancy. Primary prevention or population surveillance involves educating the general public, filtering water, improving farm hygiene to reduce animal infection, and offering prenatal education to pregnant women or women of reproductive age so that they can avoid toxoplasmosis through adopting simple behavioral measures. Evidence supporting prenatal education to prevent congenital toxoplasmosis is limited. It does indicate that prenatal education can change pregnant women's behavior to avoid risk factors for toxoplasmosis infection during pregnancy. The one controlled trial identified by the review authors was from Canada and involved 432 women who were randomly assigned to a 10 minute presentation about toxoplasmosis prevention that focused on cat, food and personal hygiene during their first prenatal class, or to their usual prenatal class.
Losses to follow up of the women participating in prenatal classes were high and 285 completed the post test questionnaire in the third term of pregnancy. Only 5% of the intervention women recalled having obtained specific information on toxoplasmosis prevention during prenatal classes.
We did not find any randomized trials providing data on change of congenital toxoplasmosis rate or exposure to toxoplasmosis in the blood (and seroconversion) during pregnancy.