Among 1101 women undergoing
legal abortion by vacuum aspiration within 14 weeks of gestation, 69 (6.3%) harboured Chlamydia trachomatis in the cervix and/or urethra. Of the chlamydia-positive women, 16 (23.2%) developed
endometritis and 10 (14.5%) developed
salpingitis during the first postoperative month. The corresponding figures among the chlamydia-negative women were 59 (5.7%) and 5 (0.6%). These differences are highly significant (p less than 0.001). To study the significance of systemic and local humoral immunity to C. trachomatis in these complications, chlamydial
antibodies were determined in serum and cervical secretions. No difference in frequency of local
IgA antibodies in chlamydia-positive women was observed between those with and those without complications. On the other hand, there was a strong indication that chlamydia-positive women who developed
salpingitis had a lower mean titer (17) of serum
IgG chlamydial
antibodies than carriers without symptoms (82, p less than 0.02). The group of
endometritis patients did not differ in this respect from chlamydia-positive women who were free of infectious complications. These results suggest that C. trachomatis may be an etiologic agent in postabortal
salpingitis and probably also in
endometritis. Serum
antibodies seemed to offer some protection against
salpingitis in chlamydia-positive cases, whereas local
antibodies did not.