We examined the prevalence of chlamydial infection in a population of pregnant women. Influence of C. trachomatis on pregnancy outcome, delivery, and their infants were observed. Eleven of the 237 women (4.6%) were C. trachomatis antigen detected from endocervical specimen. Of the 237 pregnant women, 85 (35.9%) women were IgG antibody positive, and 38 (16.1%) women were IgG and IgA antibody positive in the serum samples. Eight (72.7%) of 11 women who were antigen positive were IgA antibody positive.
The prevalence of past abortion in the seropositive group was significantly higher than in those of the seronegative group (p<0.001).
In a prospective study, prevalence of threatened abortion and preterm labor in the seropositive group was significantly higher than of those in the seronegative group. The mean duration of gestation weeks and the mean birth weight of infants in the seropositive group was significantly lower than of those in the seronegative group. Moreover the prevalence of placenta previa was 5%(3/60) in the IgG antibody positive group, 7.1%(2/28) in the IgG and IgA antibody positive group, and 0%(0/85) in the seronegative group.
Nasopharyngeal specimen were obtained from 25 infants of one month old whose cord bloods were seropositive. Of the 25 mothers, 17 mothers were IgG and IgA antibody positive, and Eight mothers were IgG positive but IgA negative. C. tracnomatis antigen were detected from six mothers who were all IgG and IgA antibody positive.
Four of the six infants born of both antigen and IgA antibody positive mothers were antigen positive in the nasopharyngeal swabs. Four of the eleven infants born of IgA antibody positive but antigen negative mothers were also antigen positive. On the other hand, none of the eigth infants born of IgA negative mothers were antigen positive. From those results, the detection of IgG and IgA antibody may be reasonable to accept as the criterion of C. trachomatis infection in a study of this kind.