Meloxicam effectively inhibits preterm labor uterine contractions in a chronically catheterized pregnant sheep model: Impact on fetal blood flow and fetal-maternal physiologic parameters

Objective

Preterm birth occurs in 5% to 10% of all pregnancies and is associated with considerable neonatal mortality and morbidity. Effective and safe drugs to prevent preterm labor are not currently available. We have hypothesized that the nonsteroidal anti-inflammatory drug meloxicam, a more selective cyclooxygenase-2 inhibitor will successfully inhibit labor but avoid the complications associated with inhibition of cyclooxygenase-1.

Study design

Preterm labor was induced in chronically catheterized sheep by RU486 administration. Animals were then randomized to receive maternal infusions of saline (n = 5) or meloxicam (n = 4) for 48 hours or until delivery when the animals were killed and tissues and blood samples collected.

Results

Maternal infusion of meloxicam inhibited uterine contractions, increasing contraction duration, and attenuating frequency and amplitude. Saline-treated animals progressed to delivery. Administration of meloxicam was not associated with any change in fetal or maternal blood gas status, osmolality, arterial pressure, heart rate, or fetal blood flows.

Conclusion

Meloxicam may represent a potentially safe and effective tocolytic agent.

Key words: Preterm labor, Pregnant sheep model, Meloxicam, Cyclooxygenase enzyme, Prostaglandins