Ectopic pregnancy and chlamydial serology

To determine the prevalence of humoral IgG antibodies to Chlamydia trachomatis in women with tubal pregnancies.

A study was made of 49 women with tubal pregnancies. The control group consisted of 50 pregnant women without any known fertility problems.

Compared with the pregnant group of women, a statistically significant higher prevalence of chlamydial IgG antibody titer > or = 64 was observed among the patients with gross abnormalities in the fallopian tube contralateral to the ectopic gestation (P = 0.002). The differences in geometric mean titer (GMT) were also statistically significant (P = 0.0004) between those two groups. The recall frequency of past pelvic inflammatory disease (PID) was increased 5-6-fold in patients with ectopic pregnancy, compared with the intrauterine pregnant women. Twenty-five of 30 patients (83%) with ectopic pregnancy and macroscopic tubal sequelae recalled a history of PID. The prevalence of chlamydial IgG antibody titer > or = 64 among women with a past history of PID was 75.6% (34/45), compared with 44.4% (24/54) among the women without any history of past PID history (P = 0.002). Concerning GMT, the numbers were 27 and 154 among women with and without a past history of PID, respectively (Fig. 2).

These findings suggest that C. trachomatis is a major cause of oviductal damage, which predisposes to ectopic pregnancy.