Ureaplasma colonization of amniotic fluid and efficacy of antenatal corticosteroids for preterm lung maturation in sheep

Moss, Timothy J.M.; Nitsos, Ilias; Knox, Christine L.; Polglase, Graeme R.; Kallapur, Suhas G.; Ikegami, Machiko; Jobe, Alan H.; Newnham, John P.

doi:10.1016/j.ajog.2008.08.044

« Previous Next »American Journal of Obstetrics & Gynecology
Volume 200, Issue 1 , Pages 96.e1-96.e6, January 2009

Ureaplasma colonization of amniotic fluid and efficacy of antenatal corticosteroids for preterm lung maturation in sheep

Presented at the 53rd Annual Meeting of the Society for Gynecologic Investigation, Toronto, ON, Canada, March 22-25, 2006.

Timothy J.M. Moss, PhD
- School of Women's and Infants' Health, University of Western Australia, Perth, WA, Australia
- Department of Physiology, Monash University, Clayton,VIC, Australia
- Reprints: T. J. M. Moss, PhD, Department of Physiology, Building 13f, Monash University, Clayton, VIC, Australia 3800
Ilias Nitsos, PhD
- School of Women's and Infants' Health, University of Western Australia, Perth, WA, Australia
Christine L. Knox, PhD
- Institute of Health and Biomedical Innovation and School of Life Sciences, Queensland University of Technology, Brisbane, QLD, Australia
Graeme R. Polglase, PhD
- School of Women's and Infants' Health, University of Western Australia, Perth, WA, Australia
Suhas G. Kallapur, MD
- Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH
Machiko Ikegami, MD, PhD
- Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH
Alan H. Jobe, MD, PhD
- Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH
John P. Newnham, MD
- School of Women's and Infants' Health, University of Western Australia, Perth, WA, Australia

Received 29 January 2008; received in revised form 27 May 2008; accepted 20 August 2008.

Objective

The objective of the study was to assess the efficacy of maternal betamethasone for improving preterm lung function in the presence of inflammation induced by amniotic fluid Ureaplasma colonization.

Study Design

Ewes bearing single fetuses were randomized to receive an intraamniotic injection of Ureaplasma parvum (serovar 6; 2 × 10⁷ colony-forming units) or vehicle at 86 ± 2 days of pregnancy (mean ± SD: term is 150 days), followed by maternal intramuscular betamethasone (0.5 mg/kg) or saline, either 2 or 7 days before delivery of lambs at 123 ± 1 d.

Results

Amniotic fluid interleukin-8 was elevated by ureaplasmas (P = .049) but unaffected by betamethasone. Lung inflammation induced by ureaplasmas was not affected by betamethasone. Lung compliance was increased by Ureaplasma colonization (P = .009) and betamethasone (P = .042), and effects were additive. Lung surfactant was increased by Ureaplasma colonization (P < .001) and betamethasone 7 days (P = .001), but not 2 days, before delivery.

Conclusion

Inflammation improves preterm lung function because of increases in surfactant. Antenatal corticosteroids further augment lung function through an apparently independent mechanism.

Key words: betamethasone, infection, intrauterine inflammation, preterm birth

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This study was supported in part by US National Institutes of Health Grant HL-65397 and National Health and Medical Research Council of Australia Grants 303261 and 458477.

Cite this article as: Moss TJM, Nitsos I, Knox CL, et al. Ureaplasma colonization of amniotic fluid and efficacy of antenatal corticosteroids for preterm lung maturation in sheep. Am J Obstet Gynecol 2009;200:96.e1-96.e6.

PII: S0002-9378(08)00980-0

doi:10.1016/j.ajog.2008.08.044

« Previous Next »American Journal of Obstetrics & Gynecology
Volume 200, Issue 1 , Pages 96.e1-96.e6, January 2009

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