Comparison of Nitroglycerin and Nifedipine in Preterm Labour

Abstract

Background: Preterm labour, defined as the onset of persistent uterine contractions leading to cervical dilatation before 37 weeks of gestation, remains a leading cause of neonatal morbidity and mortality worldwide. Effective tocolytic therapy is essential to delay delivery, allowing interventions such as antenatal corticosteroids to enhance fetal lung maturity. Nitroglycerin and nifedipine are commonly used tocolytic agents, yet comparative data in local healthcare settings are limited. Objective: To compare the efficacy of nitroglycerin patch and oral nifedipine in the management of preterm labour. Study Design: Randomized controlled trial. Duration and Place of Study: The study was conducted from August 2024 to January 2025 at the Department of Obstetrics and Gynaecology, Pakistan Institute of Medical Sciences, Islamabad. Methodology: A total of 120 women aged 18–40 years with singleton pregnancies at 24–36 weeks gestation were randomized into nitroglycerin patch (n=60) or oral nifedipine (n=60) groups. Efficacy was defined as prolongation of pregnancy for at least 48 hours from onset of preterm labour. Maternal and fetal monitoring was performed throughout the intervention. Results: Oral nifedipine demonstrated higher efficacy (90.0%) compared to nitroglycerin patches (76.7%), though the overall difference was not statistically significant (p=0.299). Stratified analysis indicated significantly improved outcomes with nifedipine in women over 30 years of age (100% vs 60%, p=0.026). Conclusion: Both agents are effective for preterm labour management, with oral nifedipine showing superior efficacy, particularly in older women, supporting its use as a reliable first-line tocolytic.