Comparative efficacy of transdermal nitroglycerin and oral nifedipine in managing preterm labor: a systematic review and meta-analysis of randomized controlled trials.

Abstract

Background: Preterm delivery is the leading cause of neonatal morbidity and mortality. This study performed a systematic review and meta-analysis to compare the efficacy of transdermal nitroglycerin and oral nifedipine in managing preterm labor.

Methods: A comprehensive search was conducted across multiple MEDLINE, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials for the randomized controlled trials comparing the effectiveness of nitroglycerin vs. nifedipine in the management of preterm labor. Primary outcomes were the prolongation of pregnancy and gestational age at delivery, while secondary outcomes included maternal side effects and neonatal outcomes. Statistical analyses were performed using RevMan 5.4 electronic databases, includingsoftware.

Results: Eighteen studies were included. The meta-analysis revealed no significant difference between nitroglycerin and nifedipine in prolonging pregnancy for 48 h (RR = 0.93, 95% CI 0.81-1.07, p = 0.3), 7 days (RR = 0.99, 95% CI 0.88-1.11, p = 0.88), or beyond 7 days (RR = 0.92, 95% CI 0.76-1.1, p = 0.36). Both treatments showed no significant advantage in prolonging gestational age at delivery (MD = 0.25, 95% CI -0.61-1.12, p = 0.58). Nitroglycerin was associated with an increased risk of headache (RR = 2.23, 95% CI 1.23-4.05, p = 0.009), while nifedipine was linked to higher rates of tachycardia (RR = 0.51, 95% CI 0.38-0.69, p < 0.00001) and palpitations (R = 0.45, 95% CI 0.27-0.73, p = 0.001). No significant differences were observed in neonatal outcomes, including birth weight (MD = -44.28, 95% CI -266.80-178.24, p = 0.70) and NICU admission rates (RR = 0.99, 95% CI 0.61-1.59, p = 0.96).

Conclusions: Nitroglycerin and nifedipine demonstrate similar efficacy in prolonging pregnancy and influencing neonatal outcomes, though their side effect profiles differ. Nifedipine is associated with more tachycardia and palpitations, while nitroglycerin causes more headaches. Further high-quality studies are required due to current evidence's low to very low certainty.