A New born weighing 1000g is born at gestational age of 30 weeks with respiratory distress after 2–3 hours of birth. What are the diagnostic possibilities –
Pulmonar causes of neonatal res irator distress

Respiratory distress syndrome (hyaline membrane disease)
Meconium aspiration syndrome
Pneumonia
Transient tachypnea of newborn
Persistent pulmonary hypertension
Congenital malformation —> TEF, Diaphragmatic hernia, lobar emphysema, pulmonary hypoplasia.
Upper airway obustruction --> choanal atresia, vocal cord palasy, lingual thyroid.


Pulmonary hemorrhage

Coming back to question -

The newborn baby in this question is preterm neonate (born before 37 weeks).
Diaphragmatic hernia may occur in term or preterm infants and may present as respiratory distress soon after birth.
Hyaline membrane disease (HMD) is a disease of preterm neonates and present as respiratory distress during first 6 hours of life.
Bronchopulmonary dysplasia (BPD) occurs most commonly in neonate of HMD who have been treated with oxygen and positive pressure ventilation ---> Instead of showing improvement on 3rd-4th day, some infants of HMD develop an increased need of oxygen and ventilatory support. So, BPD is not a differential diagnosis of respiratory distress at 2-3 hours after birth.
Diaphragmatic hernia
HMD
Pulmonary hemorrhage
All of these