ABSTRACT
OBJECTIVES: The aim of this study was to compare the efficacy and safety of magnesium sulfate, ritodrine hydrochloride and nifedipine in the management of preterm labor. MATERIALS AND METHODS: 180 women with documented preterm labor were randomly assigned to receive magnesium sulfate (n=60), ritodrine hydrochloride (n=60) and nifedipine (n=60) as initial tocolytic therapy. 30 women with documented preterm labor were allocated to administer fluid only and bed rest as control group. Patient could be switched to another tocolytic regimen if they continued to have contractions or side effects. The main outcome variables examined were days gain in utero, success rate, side effects and neonatal outcome. RESULTS: There were no significant differences in maternal characteristics between the groups. The days gain in utero was no statistically different in the three groups(magnesium sulfate, ritodrine hydrochloride and nifedipine) but markedly longer in the three groups than the control group (p<.01). The total success rate was similar in the three groups, but side effects were much more in the magnesium sulfate and ritodrine group than the nifedipine group (p<.05). The respiratory distress syndrome in neonate was decreased in the three groups than the control group without statistical significance. CONCLUSION: Nifedipine is an effective, safe, and well-tolerated tocolytic agent. In this retrospective study, total success rate of controlling preterm labor was similar in the three groups, but patients who received nifedipine were less side effects than magnesium sulfate or ritodrine group.