**Question:** True about transient tachypnoea of the newborn (TTN) is –

Core Concept: Transient Tachypnoea of the Newborn (TTN) is a respiratory condition affecting newborn infants, typically those born prematurely. It is characterized by rapid breathing (tachypnoea) and is usually transient, resolving within a few days.

**Why the Correct Answer is Right:** TTN is caused by the immaturity and incompetence of the newborn's lungs, particularly the alveoli, in clearing residual amniotic fluid after birth. The newborn's respiratory system is unable to generate sufficient negative intrathoracic pressure to facilitate active lung expansion post-birth. As a result, the newborn experiences tachypnoea to compensate for the inadequate lung expansion.

**Why Each Wrong Option is Incorrect:**

A. **False.** TTN typically affects premature infants who are still developing their respiratory system. It does not affect infants born at term.

B. **False.** TTN is not a sign of respiratory distress syndrome (RDS) or bronchopulmonary dysplasia (BPD), which are more severe lung disorders in premature infants.

C. **False.** TTN is not associated with meconium aspiration syndrome (MAS), which involves the inhalation of meconium during labor and is characterized by respiratory distress.

D. **False.** TTN is not a consequence of hypercapnic respiratory failure (HRF), which occurs due to inadequate oxygenation and carbon dioxide removal, leading to increased blood CO2 levels.

**Clinical Pearl:** TTN is generally a self-limiting condition that resolves within a few days as the infant's lungs mature and the alveoli become more efficient at clearing amniotic fluid. In severe cases, oxygen therapy may be required to relieve respiratory distress.

**Correct Answer:** D. **True.** TTN is associated with the inhalation of meconium during labor, which can obstruct the airways and lead to respiratory distress.

Transient Tachypnoea of the Newborn (TTN) is a common postnatal respiratory condition in premature infants, primarily caused by the immature respiratory system and inability to clear amniotic fluid efficiently from the lungs. In contrast, option D is correct as TTN is linked to meconium aspiration during labor, which can obstruct airways and cause respiratory distress.