A term neonate develops respiratory distress at 6 hours of life. Chest X-ray shows a ground-glass appearance with an air bronchogram. The mother had elective Caesarean section at 38 weeks without labour. On day 2, the respiratory distress resolves completely. Surfactant was NOT required. The mechanism of the transient pulmonary disorder is:
- A Delayed resorption of foetal lung fluid due to absence of labour-induced catecholamine surge ✓
- B Surfactant deficiency from immature type II pneumocytes
- C Meconium aspiration causing chemical pneumonitis
- D Group B Streptococcus pneumonia from vertical transmission
Explanation
Transient tachypnoea of the newborn (TTN) results from delayed clearance of foetal lung fluid. During labour, catecholamine surges activate epithelial sodium channels (ENaC) in alveolar epithelial cells, switching fluid secretion to active absorption. In elective CS without labour, this catecholamine surge is absent, leading to delayed resorption of foetal lung fluid. TTN is the most common cause of respiratory distress in term neonates after elective CS, presents with tachypnoea and ground-glass appearance, is self-limited (resolves within 24–72 hours), and does not require surfactant.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.