Amniotic Fluid Findings in Women with High Levels of Chlamydial Antibody

A study was undertaken to examine possible transplacental passage of Chlamydia trachomatis from pregnant women who were seropositive for chlamydia, but with no cervical C. trachomatis infection. Forty asymptomatic pregnant women, scheduled for diagnostic amniocentesis at 15–19 weeks of gestation, were tested for the presence of high serum IgA and IgG chlamydial specific antibodies and for cervical chlamydia infection. Five (12.5 %) had both high serum IgA and IgG antibody levels and 10 (25 %) had high serum IgG antibody levels. Overall, 15 (37.5%) had high serum chlamydia specific antibody levels (all were free of cervical chlamydial infection). The evaluation of the amniotic fluid specimens of these 15 seropositive pregnant women, who were free of cervical chlamydial infection, proved negative for direct C. trachomatis antigen detection and for chlamydial IgA and IgG specific antibodies. These negative results could be attributed to the lack of transplacental passage of C. trachomatis or to the antimicrobial activity of amniotic fluid against C. trachomatis, which has been previously described. The discrepancy between maternal infection and maternal serum antibody levels may suggest that the serologic test does not predict the presence of an antigen in the cervix.