Chlamydia trachomatis and Adverse Pregnancy Outcomes: Meta-analysis of Patients With and Without Infection

We conducted a meta-analysis to determine the association between Chlamydia trachomatis and adverse perinatal outcomes. Electronic databases were searched between 1970 and 2013. Included studies reported perinatal outcomes in women with and without chlamydia. Summary odds ratios were calculated using fixed- and random-effects models. Study bias was assessed using a Funnel Plot and Begg's test. Of 129 articles identified, 56 studies met the inclusion criteria encompassing 614,892 subjects. Chlamydia infection in pregnancy was associated with preterm birth (OR = 1.27, 95% CI 1.05, 1.54) with a large quantity of heterogeneity (I (2) = 61%). This association lost significance when limiting the analysis to high-quality studies based on the Newcastle-Ottawa Scale. Chlamydia infection in pregnancy was also associated with preterm premature rupture of membranes (OR = 1.81, 95% CI 1.0, 3.29), endometritis (OR 1.69, 95% CI 1.20, 2.38), low birthweight (OR 1.34, 95% CI 1.21, 1.48), small for gestational age (OR 1.14, 95% CI 1.05, 1.25) and intrauterine fetal demise (OR 1.44, 95% CI 1.06, 1.94). This review provides evidence that chlamydia in pregnancy is associated with a small increase in the odds of multiple adverse pregnancy outcomes. The literature is complicated by heterogeneity and the fact that the association may not hold in higher quality and prospective studies or those that use more contemporary nucleic acid testing.