Abstract

OBJECTIVE: To determine the efficacy and safety of nifedipine as a tocolytic agent in women with preterm labor. STUDY DESIGN: A systematic review and metaanalysis of randomized controlled trials. RESULTS: Twenty-six trials (2179 women) were included. Nifedipine was associated with a significant reduction in the risk of delivery within 7 days of initiation of treatment and before 34 weeks' gestation, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage, neonatal jaundice, and admission to the neonatal intensive care unit when compared with beta(2)-adrenergic-receptor agonists. There was no difference between nifedipine and magnesium sulfate in tocolytic efficacy. Nifedipine was associated with significantly fewer maternal adverse events than beta(2)-adrenergic-receptor agonists and magnesium sulfate. Maintenance nifedipine tocolysis was ineffective in prolonging gestation or improving neonatal outcomes when compared with placebo or no treatment. CONCLUSION: Nifedipine is superior to beta(2)-adrenergic-receptor agonists and magnesium sulfate for tocolysis in women with preterm labor.