Prenatal education for congenital toxoplasmosis

  • Review
  • Intervention




Congenital toxoplasmosis is considered a rare but potentially severe infection. Prenatal education about congenital toxoplasmosis could be the most efficient and least harmful intervention, yet its effectiveness is uncertain.


To assess the effects of prenatal education for preventing congenital toxoplasmosis.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2007), CENTRAL (The Cochrane Library 2007, Issue 3), MEDLINE (1966 to November 2007), EMBASE (1980 to November 2007), CINAHL (1982 to November 2007), LILACS (1982 to November 2007) IMEMR (1984 to November 2007), and reference lists of relevant papers, reviews and websites.

Selection criteria

Randomized and quasi-randomized controlled trials (RCT) of all types of prenatal education on toxoplasmosis infection during pregnancy.

Data collection and analysis

Three authors independently assessed study quality and extracted data.

Main results

One cluster-randomized controlled trial (432 women) met the inclusion criteria. However, the overall methodological quality was poor. The authors did not report measure of association but only provided P values (P less than 0.05) for all outcomes. The authors concluded that prenatal education can effectively change pregnant women's behavior as it increased pet, personal and food hygiene. There are no randomized trials on the effect of prenatal education on congenital toxoplasmosis rate, or toxoplasmosis seroconversion rate during pregnancy, but three observational studies consistently suggest that prenatal education might have a positive impact on these outcomes.

Authors' conclusions

Even though primary prevention of congenital toxoplasmosis is considered a desirable intervention, given the lack of related risks compared to secondary and tertiary prevention, its effectiveness has not been adequately evaluated. There is very little evidence from RCTs that prenatal education is effective in reducing congenital toxoplasmosis even though evidence from observational studies suggests it is. Given the lack of good evidence supporting prenatal education for congenital toxoplasmosis prevention, further RCTs are needed to confirm any potential benefits and to further quantify the impact of different sets of educational intervention.

Plain language summary

Prenatal education for congenital toxoplasmosis

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.