Toxoplasmosis infection is caused by a parasite, Toxoplasma gondii. Eating or handling raw or insufficiently-cooked meat, not washing hands thoroughly after gardening, handling contaminated soil or water, or contact with cats' faeces can cause infection. Usually it is asymptomatic and self-limiting. Primary prevention involves educating the general public, filtering water and improving farm hygiene to reduce animal infection.

If pregnant women have not previously been exposed to the parasite and develop antibodies while pregnant, the infection can be transmitted from the mother to the fetus (congenital toxoplasmosis). This is rare but potentially has serious consequences such as 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 early in pregnancy. Pregnant women are often unaware of risk factors for congenital toxoplasmosis. Offering prenatal education could mean that women adopt simple behavioral measures to avoid toxoplasmosis.

This review included two randomized controlled trials (involving 5455 women). Data could not be combined because each trial measured effectiveness in different ways. One study was from Canada and involved 432 women randomly assigned to a 10-minute presentation during a prenatal class about toxoplasmosis prevention or to a usual prenatal class. Losses to follow-up were high and 285 completed the post-test questionnaire in the third trimester. Only 5% of the intervention women recalled having obtained information on toxoplasmosis prevention during prenatal classes. However, the authors concluded that prenatal education can effectively change pregnant women's behavior as it increased pet, personal and food hygiene. The other trial conducted in France involved 5023 pregnant women with no evidence of toxoplasmosis infection (seronegative) who were randomly assigned to receive a brochure and an audiotape containing information for toxoplasmosis prevention, or to a usual prenatal class. Losses to follow-up were high and 2790 completed both pre-test and post-test questionnaire on behavior (44.5% loss to follow-up), whereas 3949 women were tested for blood antibodies (22.4% loss to follow-up). Women's behavior did not change after the intervention. Similarly, the seroconversion rate did not differ between groups (13 out of 2591 women seroconverted in the intervention and four out of 1358 in the control group).

Both trials were judged as having low methodological quality as assessed by the GRADE approach. This limits our confidence in the results. Evidence supporting prenatal education to prevent congenital toxoplasmosis is therefore limited.