[Relation between abnormal pregnancies and Toxoplasma gondii infection]

3,012 pregnant women were divided into three groups according to the status of Toxoplasma gondii infection, and the pregnancy outcomes were followed up. Results showed that the total incidence rates of spontaneous abortion, premature birth, still birth and congenital defects were 0.70, 3.39, 0.83 and 0.90% respectively. The incidence rates of the four groups of abnormal pregnancies having serologically diagnosed recent or active infection were significantly higher than that having no evidence of infection. The relative risk estimates (ORmh) of the 4 groups were 7.01, 3.44, 8.76 and 9.34% respectively. The incidence rates of the groups diagnosed as having past infection were not significantly different from that having no evidence of infection. Analysis of the time lapse from positive serodiagnosis to the appearance of abnormal pregnancies showed that the development of congenital defects was statistically related with Toxoplasma gondii infection in the first trimester of gestation.