Initial and repeat screening for Chlamydia trachomatis during pregnancy.

OBJECTIVES: The objective of this study is to determine the prevalence of Chlamydia trachomatis and risk factors for positive repeat tests in a high-risk population presenting for early prenatal care. METHODS: We completed a retrospective cohort study of 2,484 women who initiated prenatal care prior to 20 weeks gestation, delivered, and received testing for cervical C. trachomatis at Grady Memorial Hospital or a Grady-affiliated clinic between July 1, 1993 and December 31, 1994. We calculated adjusted odds ratios (OR) for selected risk factors for a positive initial test and for a positive subsequent test after an initial negative test. RESULTS: The prevalence of C. trachomatis was 14.8%. At initial testing, 10.4% of the women were positive. If the initial test was negative, 5.7% had a positive subsequent test; but if the initial test was positive, 32.0% had a positive subsequent test (P < 0.001). The variables significantly and independently associated with a positive initial test were black race/ethnicity, age less than 25, unmarried, and less than a high-school education (adjusted OR of 1.66, 3.53, 2.18, and 1.81, respectively). Variables significantly and independently associated with a positive subsequent test after a negative initial test were white race/ethnicity, black race/ethnicity, age less than 25, and less than a high-school education (adjusted OR 8.69, 7.77, 4.12, and 2.27, respectively). CONCLUSIONS: In our inner-city population, most pregnant women have risk factors suggesting the need to rescreen for C. trachomatis in the second half of pregnancy.