Suboptimal prenatal screening of Chlamydia trachomatis and Neisseria gonorrhoeae infections in a Montréal birthing and tertiary care centre: A retrospective cohort study

Abstract

Background: The Canadian Paediatric Society no longer recommends the use of universal ocular prophylaxis with erythromycin ointment to prevent ophthalmia neonatorum. Screening for Chlamydia trachomatis and Neisseria gonorrhoeae in all pregnant women is considered the most effective way of preventing vertical transmission and ophthalmia neonatorum. Objective: The aims of this study were to assess prenatal screening rates of C. trachomatis and N. gonorrhoeae and to compare sociodemographic factors between those screened and those not screened. Methods: The list of all women who delivered at a tertiary care hospital in Montréal, Québec, between April 2015 and March 2016, was cross-referenced with the list of samples tested for C. trachomatis and N. gonorrhoeae. Maternal medical records were reviewed for demographic, prenatal and diagnostic information. Results: Of 2,688 mothers, 2,245 women were screened at least once, but only 2,206 women had at least one valid C. trachomatis and N. gonorrhoeae result the day of delivery (82.1%; 95% CI: 80.6%–83.5%). Infection was detected in 46/2,206 (2.1%) screened women: 42 had C. trachomatis infection, two had N. gonorrhoeae infection and two were co-infected. C. trachomatis infection was more frequent in women younger than 25 years (9.8%; 95% CI: 6.7%–13.8%) than in older women (0.8%; 95% CI: 0.4%–1.3%; p<0.001). Each increase in parity decreased the probability of being tested (adjusted odds ratio=0.89; 95% CI: 0.80%–0.97%; p=0.01). Of those with an initial negative test result, 35/267 (13.1%; 95% CI: 9.3%–17.8%) of women younger than 25 years and 122/1,863 (6.6%; 95% CI: 5.5%–7.8%; p<0.001) of women aged 25 years and older were retested. Subsequent infection was detected in 4/35 (11%) women, all younger than 25. Conclusion: Suboptimal screening rates for C. trachomatis and N. gonorrhoeae suggest that current universal ocular prophylaxis cannot be discontinued. Repeating universal screening should be considered, especially among those younger than 25 years.