STRATEGY FOR SCREENING PREGNANT-WOMEN FOR CHLAMYDIAL INFECTION IN A LOW-PREVALENCE AREA

Objective: To assess the prevalence and risk factors for chlamydial in fection in pregnant women in the Quebec City area and to propose strat egies for a screening program. Methods: From january 1990 to July 1991 , pregnant women from six centers were cultured for Chlamydia trachoma tis. One hundred thirty-six with positive results and 536 with negativ e results were included in a case-control study on risk factors for th is infection. Results: The prevalence of C trachomatis was 1.9% (136 o f 7305). In a logistic regression analysis, young age (P < .0001, test for trend), nulliparity (odds ratio [OR] 3.3; P < .00001), and a new sexual partner in the last year (OR 3.3; P = .0012) were independently associated with infection. With screening restricted to pregnant wome n under age 25 or those with at least one risk factor, 81.7% of women positive for C trachomatis would have been detected, whereas only 40.6 % of all women would have been cultured. Conclusion: In a low-prevalen ce area for chlamydial infection in pregnant women, pre-screening crit eria could optimize the use of specific diagnostic tests.