Risk of Chlamydia trachomatis infection during pregnancy: effectiveness of guidelines-based screening in identifying cases.

Our goal was to define the risk factors for Chlamydia trachomatis (CT) infection among pregnant women at a large urban medical centre. In a retrospective study, clinical records at a US maternity unit from July 2005 through February 2008 were reviewed. The study population included all pregnant women with a singleton newborn of at least 20 weeks gestation and antenatal care information. Logistic regression was used to analyse the association between a positive CT test and demographic, behavioural and prenatal care variables. A total of 2127 women were included in this analysis. The prevalence of CT infection was 4.7%. Cases were more likely to be younger, black and single. Other risk factors included tobacco use and Neisseria gonorrhoeae infection. Our findings suggest that factors other than age may impact upon the diagnosis of CT in pregnant women and that a more comprehensive testing strategy should be considered.