All the following are true about transient tachypnea of newborn except

Transient Tachypnea of Newborn (TTN) Transient tachypnea of the newborn is a benign self-limiting disease occurring usually in term neonates and is due to delayed clearance of lung fluid. These babies have tachypnea with minimal or no respiratory distress. Chest X-ray may show hyperexpanded lung fields, prominent vascular marking and prominent interlobar fissure. Oxygen treatment is often adequate. Prognosis is excellent. Ref: Paediatrics; O.P. Ghai; 8th edition; Page no: 171