Background: Chlamydia trachomatis is the most prevalent bacterial sexually transmitted infection globally and is associated with serious reproductive complications, including ectopic pregnancy. The presence of anti-chlamydial immunoglobulin G (IgG) antibodies has been linked to a higher risk of ectopic pregnancy. This study aimed to compare the frequency of Chlamydia trachomatis infection in women with ectopic pregnancy versus those with normal intrauterine pregnancies.
Methods: A case-control study was conducted over 10 months (February–December 2019) at the Department of Obstetrics and Gynecology, Azadi Teaching Hospital, Kirkuk, Iraq. A total of 86 pregnant women were enrolled: 43 with confirmed ectopic pregnancy (case group) and 43 with early normal intrauterine pregnancies (control group). Women with a history of ectopic pregnancy, infertility, tubal surgery, smoking, or intrauterine device use were excluded. Serum anti-chlamydial IgG titers were measured in all participants.
Result: There were no statistically significant differences between the groups regarding age, gestational age, body mass index, or parity. Anti-chlamydial IgG was positive in 39.5% of women with ectopic pregnancy compared to 16.3% in the control group. The mean antibody titer was significantly higher in the ectopic pregnancy group. A titer above 9.98 NTU may predict the risk of ectopic pregnancy. No significant correlations were found between antibody titer and demographic or clinical parameters.
Conclusions: A higher frequency and titer of anti-chlamydial antibodies were observed in women with ectopic pregnancy. These findings suggest a potential role of chlamydial infection in the pathogenesis of ectopic pregnancy.