Toxoplasma antibodies and spontaneous abortion.

One hundred and fifty-two women with spontaneous abortion were investigated by hemagglutination (HA) and immunofluorescence antibody (IFA) tests for toxoplasmosis. In 48 cases, quantitive immunoglobulin (Ig) studies and mouse inoculation with gestational material were performed. Positive toxoplasma antibody titers were observed in 62 cases (40.8%) using HA and in 52 cases (38.2%) using IFA. This prevalence was significantly higher than that observed in 80 normal women who served as controls. Toxoplasma gondii was isolated in two cases. No correlation was found between antibody titers and IgG, IgM or IgA levels. We conclude that toxoplasmosis should be considered as the cause of abortion when a patient's antibody titer exceeds 1:256.