Prenatal screening and diagnosis of congenital toxoplasmosis: a review of safety issues and psychological consequences for women who undergo screening.

As part of the EUROTOXO initiative, this review focuses on the potential risks associated with prenatal testing for congenital toxoplasmosis. We first review the evidence on the risks of adverse events associated with amniocentesis, which is required for definitive diagnosis of toxoplasmosis infection in the fetus, and for which the most important risk is fetal loss. To date, there has been only one randomized trial to document risks associated with amniocentesis. This trial, which was conducted in 1986, reported a procedure-related rate of fetal loss of 1.0% (95% CI, 0.3-1.5). However, evidence from available controlled studies suggests that the pregnancy loss associated with mid-trimester amniocentesis may be lower. Potential psychological consequences of prenatal testing for congenital toxoplasmosis include parental anxiety due to false positive results and uncertainties related to prognosis of children with a prenatal diagnosis of congenital toxoplasmosis. Parental anxiety may be particularly important in screening strategies that include more frequent screenings, which may in turn entail substantial, and at times unnecessary, anxiety or other negative consequences for women and their families. These negative psychological outcomes should be balanced against the benefits of testing, which can allow women to make an informed choice regarding the pregnancy.