Related Experiment Video
Updated: Jul 1, 2026
Using Ex Vivo Upright Droplet Cultures of Whole Fetal Organs to Study Developmental Processes during Mouse Organogenesis
Published on: October 21, 2015
Cyclooxygenase-1-selective inhibition prolongs gestation in mice without adverse effects on the ductus arteriosus
Charles D Loftin1, Darshini B Trivedi, Robert Langenbach
1Laboratory of Environmental Carcinogenesis and Mutagenesis, National Institutes of Health, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA. langenbach@niehs.nih.gov
Cyclooxygenase-1 (COX-1) inhibitors effectively delay preterm labor without harming the fetus. This contrasts with COX-2 inhibitors, which cause adverse effects on the fetal ductus arteriosus (DA), suggesting COX-1 selective drugs are safer for treating preterm birth.
Area of Science:
- Reproductive biology
- Pharmacology
- Neonatal medicine
Background:
- Preterm delivery is a major cause of neonatal mortality and morbidity.
- Non-selective cyclooxygenase (COX) inhibitors like indomethacin delay labor but pose risks to fetal and neonatal health, particularly affecting the ductus arteriosus (DA).
- Understanding the distinct roles of COX-1 and COX-2 isoforms is crucial for developing safer tocolytic agents.
Purpose of the Study:
- To investigate the specific roles of COX-1 and COX-2 in labor initiation and ductus arteriosus (DA) regulation during pregnancy in a mouse model.
- To evaluate the safety and efficacy of isoform-selective COX inhibitors for delaying preterm labor.
Main Methods:
- Utilized isoform-selective cyclooxygenase inhibitors in pregnant mice.
- Administered inhibitors chronically during late pregnancy (gestation days 15-18) and acutely near term (gestation day 18).
- Assessed effects on labor initiation, neonatal mortality, and fetal/neonatal ductus arteriosus (DA) patency and closure.
Main Results:
- Chronic COX-2 inhibition increased neonatal mortality by inhibiting DA closure post-birth.
- Acute COX-2 inhibition near term constricted the fetal DA.
- COX-1 inhibition effectively delayed both full-term and lipopolysaccharide (LPS)-induced preterm labor without adverse effects on the DA.
Conclusions:
- Inhibition of COX-2 may be responsible for fetal ductus arteriosus (DA) constriction and patent DA in neonates observed with non-selective COX inhibitors.
- COX-1 selective inhibitors represent a promising therapeutic strategy for delaying preterm labor with a potentially improved safety profile for fetal and neonatal health.
