Comparison of Nifedipine Versus Nitroglycerin Patch in the Management of Preterm Labor: A Prospective Comparative Cohort Study

BackgroundPreterm labor (PTL) is a major contributor to neonatal morbidity and mortality worldwide, posing a significant global public health concern.The goal of tocolytic therapy is to delay labor sufficiently to allow administration of antenatal corticosteroids and transfer to a facility with neonatal intensive care services.This study evaluated the association of oral nifedipine and transdermal nitroglycerine patch treatment with successful arrest of spontaneous PTL. MethodsA prospective cohort study with a comparative design was undertaken at Holy Family Hospital, Rawalpindi, Pakistan.A total of 375 women with spontaneous PTL (28-36+6 weeks of gestation) were recruited, with 188 receiving oral nifedipine and 187 receiving a transdermal nitroglycerine patch.The main outcome was successful labor arrest for at least 48 hours.We used logistic regression, adjusting for maternal age, gestational age at admission, and parity, to account for measured baseline factors. ResultsLabor arrest was successful in 142/188 (75.5%) women who received oral nifedipine and in 112/187 (59.9%) who received the transdermal nitroglycerine patch (RR = 1.26, 95% CI: 1.09-1.46;p = 0.001).Treatment with oral nifedipine was associated with higher odds of successful labor arrest after adjustment for maternal age, gestational age at admission, and parity (AOR = 2.13, 95% CI: 1.35-3.36;p = 0.001).Successful treatment was independently associated with increasing gestational age at admission, while increasing maternal age and parity were associated with decreased odds of successful labor arrest. ConclusionIn this single-center prospective comparative cohort, oral nifedipine was associated with a higher probability of successful short-term labor arrest than transdermal nitroglycerin after adjustment for selected measured covariates.Given the non-randomized design and potential for residual confounding, these findings should not be interpreted as evidence of causal superiority.Randomized controlled trials are needed for definitive comparative assessment.