Prenatal Chlamydia trachomatis infection increases the risk of preeclampsia.

The relationship between Chlamydia trachomatis (CT) and preeclampsia was examined longitudinally among 205 cases and 423 normotensive controls nested within the Collaborative Perinatal Project. Antibodies were analyzed at a first prenatal visit (mean 14.2 weeks) and at delivery. Prenatal infections were identified as IgG/IgM seroconversion or a four-fold rise in IgG antibody titers. Although serological evidence of incident prenatal CT infection was uncommon (n=9, 1.4%) in this general pregnant population, infected women were more likely to develop preeclampsia, after adjustment for maternal age, body mass index, smoking status, race and time between blood draws (ORadj 7.2, 95% CI 1.3 - 39.7).