Births and ectopic pregnancies in a large cohort of women tested for Chlamydia trachomatis

Recent studies show divergent results concerning the risk of ectopic pregnancy following Chlamydia trachomatis (CT) infection.

Our goal was to investigate future reproductive health outcomes (births and ectopic pregnancies) among women tested for CT.

Our cohort consisted of 20,762 women born during 1970-1984 who were tested for CT during 1990-2003. We linked CT data to data on ectopic pregnancies and births during 1990-2004. Cox regression with time-dependent covariates was used to assess the association between CT history and births/ectopic pregnancies adjusted for age at first test. Analyses with ectopic pregnancy as outcome were also adjusted for parity.

We observed 9.6 births per 100 person-years of observation among women with negative tests only and 10.2 per 100 person-years among women with at least 1 positive test (hazard ratio adjusted for age at first test, 1.07; 95% CI, 1.01-1.12). Ectopic pregnancy incidence rates were higher for women with positive test(s) compared with women with negative test only (0.24 vs. 0.13 per 100 person-years; hazard ratio adjusted for age at first test and parity, 1.82; 95% CI, 1.27-2.60). Among women with at least 1 registered pregnancy, the adjusted hazard ratio was 2.03; 95% CI, 1.28-3.22).

Although women diagnosed with CT were at higher risk for ectopic pregnancy than women with negative test results only, our study suggest that their fertility prospects were better than they would have been had CT screening not been implemented in this population. Opportunistic CT screening is an appropriate method for maintaining female reproductive health.