Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the commonest cause of respiratory distress in newborns?

1. Transient tachypnoea

2. Pneumonia

3. Bronchopulmonary dysplasia

4. Meconium aspiration syndrome

The correct answer is: Transient tachypnoea

Transient tachypnoea of the newborn (TTN) is the most common cause of respiratory distress in newborns, particularly in term and late preterm infants. This condition often occurs because of retained fetal lung fluid, which can be common in infants who are born via cesarean delivery or with rapid or complicated deliveries. In TTN, the newborn may present with rapid breathing and mild respiratory distress soon after birth, but these symptoms typically resolve within 72 hours without significant medical intervention. This condition is usually self-limiting and does not usually lead to long-term complications, which is why it is considered the most prevalent cause of respiratory distress in the newborn population. In contrast, the other conditions listed, while they can also lead to respiratory distress, occur less frequently. For instance, pneumonia may cause significant respiratory issues but is less common as a primary cause in this age group compared to TTN. Likewise, bronchopulmonary dysplasia is mainly associated with premature infants and long-term ventilation support, while meconium aspiration syndrome, although serious, is not as prevalent as TTN overall.