title: Chlamydia trachomatis infection during pregnancy associated with preterm delivery: a population-based prospective cohort study.
abstract: Chlamydia trachomatis infection is the most prevalent bacterial sexually transmitted infection and may influence pregnancy outcome. This study was conducted to assess the effect of chlamydial infection during pregnancy on premature delivery and birthweight. Pregnant women attending a participating midwifery practice or antenatal clinic between February 2003 and January 2005 were eligible for the study. From 4,055 women self-administered questionnaires and urine samples, tested by PCR, were analysed for C. trachomatis infection. Pregnancy outcomes were obtained from midwives and hospital registries. Gestational ages and birthweights were analysed for 3,913 newborns. The C. trachomatis prevalence was 3.9%, but varied by age and socio-economic background. Chlamydial infection was, after adjustment for potential confounders, associated with preterm delivery before 32 weeks (OR 4.35 [95% CI 1.3, 15.2]) and 35 weeks gestation (OR 2.66 [95% CI 1.1, 6.5]), but not with low birthweight. Of all deliveries before 32 weeks and 35 weeks gestation 14.9% [95% CI 4.5, 39.5] and 7.4% [95% CI 2.5, 20.1] was attributable to C. trachomatis infection. Chlamydia trachomatis infection contributes significantly to early premature delivery and should be considered a public health problem, especially in young women and others at increased risk of C. trachomatis infection.
authors.affiliation: The Generation R Study group, Erasmus University Medical Centre, Rotterdam, The Netherlands. rours@mac.com
authors.forename: G Ingrid J G
authors.initials: GI
authors.lastname: Rours
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Duijts
authors.forename: Henriette A
authors.initials: HA
authors.lastname: Moll
authors.forename: Lidia R
authors.initials: LR
authors.lastname: Arends
authors.forename: Ronald
authors.initials: R
authors.lastname: de Groot
authors.forename: Vincent W
authors.initials: VW
authors.lastname: Jaddoe
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: Eric A P
authors.initials: EA
authors.lastname: Steegers
authors.forename: Johan P
authors.initials: JP
authors.lastname: Mackenbach
authors.forename: Alewijn
authors.initials: A
authors.lastname: Ott
authors.forename: Hendrina F M
authors.initials: HF
authors.lastname: Willemse
authors.forename: Elizabeth A E
authors.initials: EA
authors.lastname: van der Zwaan
authors.forename: Roel P
authors.initials: RP
authors.lastname: Verkooijen
authors.forename: Henri A
authors.initials: HA
authors.lastname: Verbrugh
mesh_terms: D000328:Adult; D002690:Chlamydia Infections / Q000150:complications* / Q000453:epidemiology; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D009426:Netherlands / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D047928:Premature Birth / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D012307:Risk Factors