Related Experiment Video
Updated: Jul 10, 2026
Modeling Ascending Vaginal Infection, Preterm Birth, and Neonatal Morbidity in Mice
Published on: October 10, 2025
Immunomodulators plus antibiotics delay preterm delivery after experimental intraamniotic infection in a nonhuman
Michael G Gravett1, Kristina M Adams, Drew W Sadowsky
1Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle, WA 98195-6460, USA. gravettm@u.washington.edu
Objective:
The purpose of this study was to determine whether treatment with ampicillin together with dexamethasone and indomethacin delays preterm birth that is induced by intraamniotic group B Streptococcus in a nonhuman primate model.
Study Design:
After contraction onset that was induced by group B Streptococcus (10(6) colony-forming units/mL), chronically instrumented rhesus macaques received either no treatment (controls; n = 6); ampicillin (n = 4); or ampicillin + dexamethasone + indomethacin (n = 5). Outcomes included the interval from contraction onset until delivery and concentrations of amniotic fluid inflammatory mediators.
Results:
Mean interval from contraction onset until delivery was 33 +/- 8.7 hours in controls, 82 +/- 28.0 hours with ampicillin (P = .18, vs controls), and 213 +/- 50.8 hours with ampicillin + dexamethasone + indomethacin (P = .004, vs controls). Ampicillin eradicated group B Streptococcus; however, uterine activity, amniotic fluid cytokines, prostaglandins, and matrix metalloproteinase-9 remained elevated. Ampicillin + dexamethasone + indomethacin suppressed interleukin-1beta, tumor necrosis factor-alpha, and prostaglandins E2 and F2alpha but did not alter matrix metalloproteinase expression or chorioamnionitis.
Conclusion:
The combination of ampicillin + dexamethasone + indomethacin suppressed inflammation and significantly prolonged gestation.
