Calfactant vs Poractant Alfa Using a Less Invasive Technique in Preterm Infants With Respiratory Distress Syndrome

Inclusion Criteria: * Born at a participating study center hospital. * Gestational age between 24 1/7 and 29 6/7 weeks (\<30 0/7 weeks). * Postnatal age within the first 6 hours of life. * Being on non-invasive respiratory support. * Presence of clinical and radiological findings consistent with respiratory distress syndrome (RDS). * Indication for surfactant therapy defined as a requirement for FiO₂ \>30% to achieve target oxygen saturation (SpO₂ 90-94%) while receiving noninvasive respiratory support with a minimum pressure of 6 cmH₂O. * Written informed consent obtained from a parent or legal guardian. Exclusion Criteria: * Infants who were intubated for any reason before the decision to administer surfactant. * Severe birth asphyxia, defined as the need for advanced resuscitation after birth, 10th minute Apgar score ≤5, and arterial blood gas within the first hour of life showing pH \<7.0 and base excess (BE) ≤-12. * Presence of major congenital anomalies. * Respiratory distress due to causes other than respiratory distress syndrome (RDS). * Congenital heart disease. * Congenital diaphragmatic hernia. * Pulmonary hypoplasia. * Chromosomal abnormalities. * Presence of pneumothorax. * Lack of informed consent. * Neonatal seizures presence. * Postnatal age greater than 6 hours. * Infants born outside of gestational weeks 24 1/7 - 29 6/7. * Requirement for invasive mechanical ventilation at enrollment. * Infants receiving noninvasive respiratory support with an FiO₂ requirement \<0.30.