Chlamydia trachomatis infection during pregnancy: can it cause an intrauterine infection?

In an attempt to prove the presence of intrauterine fetal chlamydial infection, sera from 26 laboring women, who tested positive for cervical chlamydial antigen in the first half of their pregnancies, and from 43 laboring women with no evidence of such infection, and sera from the cord of their delivered infants were tested for chlamydial IgA-, IgG- and IgM-specific antibodies. Nine (34.6%) of the 26 women with positive cervical infection and 5 (11.6%) of the 43 women with no identifiable cervical infection had significant antibody levels at the time of the delivery. Three of the 26 (11.5%) babies born to the mothers with positive cervical chlamydial infection early in the pregnancy and high antibody titer at delivery were found to have anti-chlamydial antibodies in their cord serum, indicating intrauterine infection; cord sera from the other 43 babies were negative for these antibodies. These findings suggest a low but possible risk of intrauterine infection in the presence of lower genital infection during pregnancy.