Comparison of Nifedipine Versus Indomethacin for Acute Preterm Labor

The purpose of this research study is to determine the best medication to stop preterm labor. Recent studies have identify nifedipine and indomethacin as the two medications that are most likely to delay delivery for 48 hours, decrease maternal side effects and decrease some complications related to preterm delivery to the neonate. Both of these medications are commonly used to stop pre-term labor, therefore it has become our institution's standard to use these two medications in the setting of preterm labor. There have been limited studies comparing these two medications directly. A total of 450 participants will be asked to participate across all study sites.