Infant acute respiratory distress syndrome is a lung disorder that affects premature infants caused by developmental insufficiency of surfactant production and structural immaturity of the lungs. The symptoms usually appear shortly after birth and may include tachypnea, tachycardia, chest wall retractions (recession), expiratory grunting, nasal flaring and cyanosis during breathing efforts.

Systemic desaturation of a liveborn baby resulting from persistent pulmonary hypertension with a patent ductus arteriosus and patent foramen ovale, such that the circulation in postnatal life follows the fetal course.