BACKGROUND AND OBJECTIVES:Congenital toxoplasmosis is associated with significant morbidity and mortality. This study investigates the prevalence of toxoplasmosis among pregnant women.DESIGN AND SETTING:A retrospective study at King Khalid University Hospital, Riyadh from September 2009 to August 2010.PATIENTS AND METHODS:Laboratory data of 2176 pregnant women screened for Toxoplasma gondii in the antenatal care unit were assessed during the study period. The mean (SD) age of the women and the duration of pregnancy were 25 (7.3) years and 18 (7.7) weeks, respectively. Data were extracted for the presence or absence of anti-T gondii immunoglobulin G (IgG) and IgM antibodies.RESULTS:Of 2176 sera tested, 1351 (62%) did not show any evidence of exposure to T gondii. The remaining 825 (38%) samples tested positive for anti-T gondii IgG antibodies, and none was found to have anti-T gondii IgM antibodies in the serum. These data reveal that a significantly high number of women in the antenatal care unit at King Khalid University Hospital in Riyadh had been exposed to T gondii.CONCLUSION:A high prevalence of toxoplasmosis among pregnant women warrants multicenter community-based investigations for assessment of T gondii infection and identification of risk factors for transmission of toxoplasmosis in general, and particularly during pregnancy.