Antenatal Corticosteroids for Fetal Lung Maturation and Prevention of Respiratory Distress Syndrome: A Systematic Review

Abstract

Preterm birth remains a major global cause of neonatal morbidity and mortality, frequently leading to respiratory distress syndrome (RDS) due to pulmonary immaturity and surfactant deficiency. Antenatal corticosteroids (ACS) are widely used to accelerate fetal lung maturation and improve neonatal respiratory outcomes. The present systematic review evaluates the physiological mechanisms, clinical effectiveness, and current clinical recommendations for antenatal corticosteroid therapy in the prevention of neonatal RDS. A structured literature review was conducted following the PRISMA framework using major databases including PubMed, Google Scholar, Scopus, and Web of Science. Relevant studies evaluating the use of betamethasone or dexamethasone in pregnant women at risk of preterm birth were screened. Ten high-quality studies, including randomized controlled trials, cohort studies, and meta-analyses, were selected for qualitative synthesis. The findings consistently demonstrate that antenatal corticosteroid therapy significantly reduces the incidence of respiratory distress syndrome, neonatal mortality, intraventricular hemorrhage, and necrotizing enterocolitis. Several landmark trials also confirm benefits in both early and late preterm pregnancies. Physiologically, corticosteroids promote differentiation of type II pneumocytes, enhance surfactant synthesis, and improve pulmonary compliance, thereby facilitating postnatal lung function. Current international guidelines recommend administration of antenatal corticosteroids for women at risk of preterm delivery within seven days between 24 and 34 weeks of gestation. Overall, antenatal corticosteroid therapy remains a cornerstone of modern perinatal care. Future research should focus on optimizing dosing strategies and evaluating long-term neurodevelopmental outcomes associated with repeated exposure.