Experimental amniotic fluid infection in sheep: effects of Ureaplasma parvum serovars 3 and 6 on preterm or term fetal sheep

Am J Obstet Gynecol. 2008 Jan;198(1):122.e1-8. doi: 10.1016/j.ajog.2007.06.065.


Objective: The objective of the study was to determine the effects in late gestation of Ureaplasma parvum serovar 3 colonization and the effects, preterm, of U. parvum serovar 6.

Study design: Ewes received an intraamniotic (i.a.) injection of U. parvum serovar 6 (20 x 10(6) colony-forming units [cfu]; n = 9), U. parvum serovar 3 (20 x 10(3) cfu; n = 6), vehicle (n = 10), or saline (n = 4) on day 80 of pregnancy (d). The lambs were delivered at 125 d (U. parvum serovar 6, n = 9; saline or media controls, n = 9) or 145 d (U. parvum serovar 3, n = 6; media controls, n = 5) for assessment of inflammation and lung maturation.

Results: I.a. ureaplasmas caused histologic chorioamnionitis but not preterm delivery. Fetal lung epithelium was colonized with ureaplasmas at both gestational ages, and pulmonary interleukin-8 levels had doubled in the ureaplasma-colonized animals, compared with the controls at 145 d. Surfactant levels in bronchoalveolar lavage fluid had increased 8-fold and 2.5-fold at 125 and 145 d, respectively, after ureaplasma injection.

Conclusion: Fetal lung inflammation and altered development accompanies ureaplasma colonization, regardless of age at delivery.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amniotic Fluid / microbiology
  • Animals
  • Animals, Newborn
  • Chorioamnionitis / microbiology
  • Chorioamnionitis / physiopathology*
  • Disease Models, Animal
  • Female
  • Fetal Organ Maturity
  • Pregnancy
  • Pregnancy, Animal*
  • Random Allocation
  • Reference Values
  • Sheep, Domestic
  • Ureaplasma / pathogenicity*
  • Ureaplasma Infections*