Change of immunoglobulin G antibody levels to Toxoplasma gondii during pregnancy in an obstetric population.

Paired sera obtained from 393 pregnant women during the first trimester and from their umbilical cords at birth were examined for immunoglobulin G antibodies to Toxoplasma gondii by enzyme-linked immunosorbent assay. The course of antibody levels in asymptomatic populations is discussed with regard to possible fetal infection during the gestational period.