Therapeutic role of nifedipine in threatened preterm labor: Current evidence and future perspectives

Preterm birth occurs in approximately 10% of all pregnancies, and is not only the leading cause of neonatal mortality but also a major contributor to short- and long-term morbidities due to immaturity. Preterm birth has also been linked to an increased risk of maternal cardiovascular and cerebrovascular diseases, making it a critical concern in both perinatal medicine and women's lifelong health. Effective treatment requires interventions during threatened preterm labor, and several tocolytic agents have been developed and used in clinical practice. However, no pharmacological agent has been shown to prolong gestation and improve neonatal outcomes. Nifedipine, a calcium channel blocker, is widely used as a first-line tocolytic agent because of its oral administration route and relatively favorable safety profile compared with other drugs. Evidence from randomized controlled trials, meta-analyses, and Cochrane reviews suggests that nifedipine can delay delivery for a short period; however, robust evidence demonstrating sustained prolongation of pregnancy or improved neonatal survival is still lacking. Moreover, data on maternal hemodynamic changes and fetal effects are limited, highlighting the need for optimal dosing strategies and monitoring protocols. In this study, we discuss the clinical significance and limitations of nifedipine in the management of threatened preterm labor and outlined future directions. Future studies should involve large and homogeneous populations, continuous assessment of maternal hemodynamics, and application of novel biomarkers to support individualized therapy. Accumulation of such evidence is expected to optimize the management of threatened preterm labor and ultimately improve outcomes for mothers and infants.