title: Antenatal exposure to Ureaplasma species exacerbates bronchopulmonary dysplasia synergistically with subsequent prolonged mechanical ventilation in preterm infants.
abstract: BACKGROUND
  The presence of microorganisms in gastric fluid in neonates at birth is postulated to reflect antenatal infection and also to be associated with the development of bronchopulmonary dysplasia (BPD).
  
  
  RESULTS
  A logistic regression analysis, after controlling for other risk factors, indicated that Ureaplasma-positive infants were not at increased risk for moderate/severe BPD (adjusted odds ratio (OR): 2.58, 95% confidence interval (CI): 0.57-6.89, P = 0.12). However, the association between the presence of Ureaplasma species and the risk for moderate/severe BPD increased significantly in infants on mechanical ventilation (MV) ≥2 wk (adjusted OR: 4.17, 95% CI: 1.62-44.1, P = 0.009). An analysis using a lung injury marker indicated that Ureaplasma-positive infants with MV ≥2 wk, but not other infants, showed higher serum KL-6 levels in samples taken from cord blood, and that KL-6 levels increased time-dependently up to 4 wk of age.
  
  
  CONCLUSIONS
  Antenatal exposure to Ureaplasma species induces lung injury prior to birth and synergistically contributes to the development of BPD in infants requiring prolonged MV (≥2 wk).
  
  
  METHODS
  We recovered gastric fluid specimens from 122 infants with gestational age (GA) <29 wk or birth weight <1,000 g to investigate whether these microorganisms influence respiratory outcome of BPD. A PCR analysis was used to detect urease and 16S ribosomal RNA (rRNA) genes to classify neonates into Ureaplasma-positive or Ureaplasma-negative infants.
authors.affiliation: Department of Neonatal Medicine and Pediatrics, Osaka Medical College, Osaka, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Inatomi
authors.forename: Shinya
authors.initials: S
authors.lastname: Oue
authors.forename: Tohru
authors.initials: T
authors.lastname: Ogihara
authors.forename: Seigo
authors.initials: S
authors.lastname: Hira
authors.forename: Masashi
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yamaoka
authors.forename: Masako
authors.initials: M
authors.lastname: Yasui
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tamai
mesh_terms: D015415:Biomarkers / Q000097:blood; D001826:Body Fluids / Q000382:microbiology; D001997:Bronchopulmonary Dysplasia / Q000453:epidemiology* / Q000628:therapy*; D005260:Female; D005312:Fetal Blood; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D016015:Logistic Models; D008297:Male; D018396:Mucin-1 / Q000097:blood; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000503:physiopathology*; D012121:Respiration, Artificial; D012189:Retrospective Studies; D012307:Risk Factors; D014509:Ureaplasma / Q000302:isolation & purification; D016869:Ureaplasma Infections / Q000150:complications*
chemical_list: D015415:Biomarkers; C060192:MUC1 protein, human; D018396:Mucin-1