Antenatal dexamethasone vs. betamethasone dosing for lung maturation in fetal sheep

Augusto F. Schmidt, Matthew W. Kemp, Paranthaman S. Kannan, Boris W. Kramer, John P. Newnham, Suhas G. Kallapur, Alan H. Jobe

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Background:Dexamethasone-phosphate (Dex-PO4) and the combination betamethasone-phosphate (Beta-PO4) + betamethasone-acetate (Beta-Ac) are the most used antenatal corticosteroids to promote fetal lung maturation. We compared fetal lung maturation induced by Beta-Ac+Beta-PO4, Dex-PO4, or Beta-PO4 alone.Methods:Pregnant ewes received two intramuscular doses 24 h apart of 0.25 mg/kg/dose of Beta-Ac+Beta-PO4, Dex-PO4 or Beta-PO4; or 2 doses of 0.125 mg/kg/dose of Beta-PO4 at 6, 12, or 24 h intervals. Fetuses were delivered 48 h after the first dose and ventilated for 30 min. We assessed ventilatory variables, vital signs, and blood gas. After ventilation pressure-volume curves were measured and lungs were sampled for analysis.Results:All treatments improved lung compliance and ventilation efficiency. Only Beta-Ac + Beta-PO4 required lower positive inspiratory pressure compared with control. Beta-Ac + Beta-PO4 and Beta-PO4 alone, but not Dex-PO4, increased the mRNA of surfactant proteins compared with control. Low-dose Beta-PO4 did not increase mRNA of surfactant proteins. There were no differences among Beta-PO4 treatment intervals.Conclusion:Beta-Ac + Beta-PO4 given as two doses 24 h apart was more effective in promoting fetal lung maturation than Dex-PO4 or Beta-PO4 alone, consistent with a prolonged exposure provided by the Beta-Ac + Beta-PO4. These results support the clinical use of combined Beta-Ac + Beta-PO4 preparations over phosphate corticosteroids alone for fetal lung maturation.

Original languageEnglish (US)
Pages (from-to)496-503
Number of pages8
JournalPediatric Research
Issue number3
StatePublished - Mar 1 2017
Externally publishedYes

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health


Dive into the research topics of 'Antenatal dexamethasone vs. betamethasone dosing for lung maturation in fetal sheep'. Together they form a unique fingerprint.

Cite this