All of the following are true about transient tachypnea of newborn except-
Transient tachypnea of Newborn o 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.
It is also called respiratory distress syndrome type II.
TTN follows -

Uneventful normal preterm or term vaginal delivery
Cesarean delivery
TTN is believed to be secondary to slow absorption of fetal lung fluid resulting in decreased pulmonary compliance and tidal volume and increased dead space therefore
also known as wet lung
Clinical manifestations o Early onset of tachypnea
Sometimes retraction or expiratory grunting
Occasionally cyanosis
Patients usually recover rapidly within 3 days
Hypoxemia, hypercapnia and acidosis are uncommon.
The lungs are generally clear without rales or rhonchi and chest roentgenogram shows  
Prominent pulmonary vascular markings o Fluid lines in the fissure o Prominent inter-labar fissure
Overaeration) Flat diaphragm o Occasionally pleural fluid.
It is a self limiting disease
It may occur after Caeserean section
It usually takes 1 month to recover
It is due to slow absorption of fetal lung fluid