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Updated: Sep 27, 2026
A Murine Model of Fetal Exposure to Maternal Inflammation to Study the Effects of Acute Chorioamnionitis on Newborn Intestinal Development
Published on: June 24, 2020
Systemic administration of betamethasone delays endotoxin-induced preterm labor in the murine model
William J Schwartz1, H Dix Christensen, J Chris Carey
1Department of Obstetrics and Gynecology, University of Oklahoma College of Medicine, USA.
Objective:
The purpose of this study was to determine whether the administration of betamethasone decreases the endotoxin-induced preterm parturition rate and inhibits the risk of cytokines in the murine model.
Study Design:
Endotoxin was administered intraperitoneally at gestational day 15 (75% of gestation). In phase I, the duration of gestation was measured in 36 gravid C3H/HeOu mice that were equally divided into four treatment groups: control, endotoxin only, and two different dose regimens of betamethasone followed by endotoxin. In phase II, maternal serum and amniotic fluid concentrations of cytokines (interleukin-1alpha, tumor necrosis factor-alpha, and interleukin-6) were measured at 4 hours after endotoxin injection in 44 gravid mice divided equally in the four treatment groups.
Results:
The group that was exposed only to endotoxin was delivered at a significantly earlier gestational age compared with the control group (16.2 +/- 0.4 days vs 19.6 +/- 0.2 days; P <.01). The two groups that were pretreated with betamethasone before the endotoxin were delivered at gestational ages similar to the control group. There was a marked increase of tumor necrosis factor-alpha and interleukin-6 levels in amniotic fluid of mice that were treated with endotoxin only compared with the control group (P <.001). No difference in cytokine levels was found in those mice that were premedicated with betamethasone compared with the control group.
Conclusion:
Antenatal administration of betamethasone to mice delayed preterm parturition that was induced by endotoxin. Elevations of amniotic fluid cytokine concentrations that were observed with endotoxin were not observed with pretreatment with betamethasone.
Insights
Betamethasone effectively delayed endotoxin-induced preterm birth in mice. This treatment also prevented harmful increases in amniotic fluid cytokines, suggesting a protective role in pregnancy.
Area of Science:
- Reproductive biology
- Pharmacology
- Immunology
Background:
- Preterm birth is a significant concern in obstetrics.
- Endotoxin administration can induce preterm labor.
- Cytokines play a role in parturition.
Purpose of the Study:
- To investigate if betamethasone can prevent endotoxin-induced preterm birth in mice.
- To determine if betamethasone affects cytokine levels associated with labor.
Main Methods:
- Mice received endotoxin to induce preterm labor.
- Different groups were pretreated with betamethasone at varying doses.
- Gestational duration and amniotic fluid cytokine levels (IL-1α, TNF-α, IL-6) were measured.
Main Results:
- Endotoxin significantly shortened gestation compared to controls.
- Betamethasone pretreatment restored gestational duration to control levels.
- Endotoxin increased amniotic fluid TNF-α and IL-6, which was prevented by betamethasone.
Conclusions:
- Antenatal betamethasone administration delays endotoxin-induced preterm parturition in a murine model.
- Betamethasone pretreatment mitigates the endotoxin-induced rise in amniotic fluid pro-inflammatory cytokines.
