Study of Inhaled Nitric Oxide (iNO) and Respiratory Outcomes in Late Preterm Infants

Inclusion Criteria: * \<48 hours of age, * 30 - 36 weeks gestational age at birth based on best estimate using obstetrical sonography (first or second trimester), solid dating criteria, or Ballard examination, * Birth weight of ≥ 1,000 g, * 5 minute Apgar score ≥5, * Requiring nasal cannula O2 \> 1 liter per minute (LPM), continuous positive pressure (CPAP), or non invasive positive pressure ventilation (NIPPV) for treatment of respiratory failure, * Requiring a fraction of inspired oxygen (FIO2) of at least 0.25 to maintain arterial oxygen saturation (SaO2) 88-94%, * Parent or guardian has signed informed consent and agrees to all study- related procedures, including those required after hospital discharge. Exclusion Criteria: * Major congenital anomaly * Intubation and surfactant in the delivery room or prior to enrollment in the Neonatal Intensive Care Unit (NICU). Excludes intubation for suctioning. * Known congenital infection (bacterial, viral), * Perinatal asphyxia (5 minute Apgar \<5, umbilical artery pH \< 7.0 or evidence of neonatal encephalopathy), * Mother and/or infant is enrolled in another clinical trial (excluding observational) or has received an investigational drug, * Has undergone or is anticipated to require a major surgical procedure within the first 48 h of life, * Any condition which could preclude receiving study drug or performing any study-related procedures, * Use of postnatal corticosteroids, * Parent or guardian is unable or unwilling to complete study procedures after hospital discharge.