A retrospective study of seroconversion against Toxoplasma gondii during 3,000 pregnancies in Stockholm.

The incidence of Toxoplasma gondii infections in Swedish women during pregnancy is largely unknown. This retrospective pilot study was performed on consecutive sera sampled from 3,094 women at delivery during 1992-93. Specific IgG anti-toxoplasma antibodies were found in 14% (450/3,094). Serum drawn from the women during the first trimester and cord blood from their children were analysed for IgG and IgM anti-toxoplasma antibodies. A seroconversion during pregnancy was found in 4 women, whose children were followed up at 4 years of age. No signs of sequelae, either neurological or ophthalmological, were found in 3 of the children. The fourth child died at 1 year of age of a disease of different aetiology. An incidence of a primary toxoplasma infection of >1/1,000 pregnancies in this pilot study justifies a larger study.