Neonatal respiratory distress due to inhalation of meconium containing amniotic fluid prior to or during delivery. Presentation may range from mild to severe. Onset may be observed during first breaths or within hours to days following birth. Characterized by tachypnea, cyanosis, grunting, and retractions. Other signs and symptoms are meconium staining on skin, nails, and trachea. There may be signs of hypoxia, hypercarbia, abdominal breathing, flattening of diaphragm, and persistent pulmonary hypertension. It can be life-threatening and require mechanical ventilation.

Aspirated meconium particulate matter can lead to infection, surfactant inactivation, pulmonary damage, pneumothorax, obstructed airway, asphyxiation, and respiratory failure of the fetus or newborn.