title: The Preterm Prediction Study: association of second-trimester genitourinary chlamydia infection with subsequent spontaneous preterm birth.
abstract: OBJECTIVE
  This study was undertaken to determine the association between genitourinary tract infection with Chlamydia trachomatis and spontaneous preterm birth.
  
  
  METHODS
  Genitourinary tract infection with C trachomatis was determined with a ligase chain reaction assay of voided urine samples collected at 24 weeks' gestation (22 weeks' to 24 weeks 6 days' gestation) and 28 weeks' gestation (27 weeks' to 28 weeks 6 days' gestation). Case patients (spontaneous preterm birth at <37 weeks' gestation; n = 190) and control subjects (delivery at >/=37 weeks' gestation, matched for race, parity, and center; n = 190) were selected from 2929 women enrolled in the Preterm Prediction Study of the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.
  
  
  RESULTS
  Genitourinary C trachomatis infection (11% overall) was significantly more common among the case patients than among the control subjects at 24 weeks' gestation (15.8% vs 6.3%; P =.003) but not at 28 weeks' gestation (12.6% vs 10.9%; P =.61). Women with chlamydia infection were more likely to have bacterial vaginosis (57.1% vs 32.9%; P =.002) and a short cervical length (</=25 mm; 33.0% vs 17.9%; P =.02) but not a body mass index <19.8 kg/m(2) (35.0% vs 23.9%; P =.17) or a positive fetal fibronectin test result (7.1% vs 9.5%; P =.62). After adjustment for risk factors for spontaneous preterm birth, women with C trachomatis infection at 24 weeks' gestation were 2 times as likely as uninfected women to have a spontaneous preterm birth at <37 weeks' gestation (odds ratio, 2.2; 95% confidence interval, 1.03-4.78) and 3 times as likely to have a spontaneous preterm birth at <35 weeks' gestation (odds ratio, 3.2; 95% confidence interval, 1.08-9.57).
  
  
  CONCLUSIONS
  Genitourinary C trachomatis infection at 24 weeks' gestation was associated with a 2-fold to 3-fold increased risk of subsequent spontaneous preterm birth.
authors.affiliation: National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network, the University of Alabama at Birmingham, Birmingham, AL 35249-7333, USA.
authors.forename: W W
authors.initials: WW
authors.lastname: Andrews
authors.forename: R L
authors.initials: RL
authors.lastname: Goldenberg
authors.forename: B
authors.initials: B
authors.lastname: Mercer
authors.forename: J
authors.initials: J
authors.lastname: Iams
authors.forename: P
authors.initials: P
authors.lastname: Meis
authors.forename: A
authors.initials: A
authors.lastname: Moawad
authors.forename: A
authors.initials: A
authors.lastname: Das
authors.forename: J P
authors.initials: JP
authors.lastname: Vandorsten
authors.forename: S N
authors.initials: SN
authors.lastname: Caritis
authors.forename: G
authors.initials: G
authors.lastname: Thurnau
authors.forename: M
authors.initials: M
authors.lastname: Miodovnik
authors.forename: J
authors.initials: J
authors.lastname: Roberts
authors.forename: D
authors.initials: D
authors.lastname: McNellis
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002690:Chlamydia Infections / Q000150:complications* / Q000453:epidemiology; D002692:Chlamydia trachomatis / Q000235:genetics / Q000302:isolation & purification; D011088:DNA Ligases; D004269:DNA, Bacterial / Q000652:urine; D005260:Female; D052776:Female Urogenital Diseases / Q000382:microbiology*; D005784:Gene Amplification; D005865:Gestational Age; D006801:Humans; D007752:Obstetric Labor, Premature / Q000382:microbiology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D004269:DNA, Bacterial; D011088:DNA Ligases