Prevalence of IgA and IgG antichlamydial antibodies in women in the third trimester of pregnancy.

The prevalence of serum antichlamydial IgA and IgG antibodies was investigated by screening 77 randomly selected patients who were in the third trimester of pregnancy. An indirect immunoperoxidase assay that quantitates IgA and IgG was used for screening. Twenty-five women had both IgA and IgG antibodies; an additional ten women had only IgG antibodies. These findings suggest that greater than 45 percent of pregnant women tested had been exposed to Chlamydia trachomatis, and more than 32 percent had evidence of active infection.