A pregnant woman with a son affected by spinal muscular atrophy (SMA) type 2 is expecting a male fetus. What is the risk that the fetus will be affected?

Correct Answer: B

Rationale: SMA is an autosomal recessive disorder, meaning each pregnancy has a 1 in 4 chance of being affected if both parents are carriers.

Correct Answer: A

Rationale: Hypoxia is the most common cause of non-cardiac neonatal arrhythmias, as it can lead to disturbances in the electrical conduction system of the heart, particularly in newborns with respiratory distress.

Correct Answer: B

Rationale: Surfactant replacement therapy is the most effective treatment for respiratory distress syndrome (RDS) in preterm infants, reducing alveolar collapse and improving gas exchange. It is often given via endotracheal tube soon after birth.

Correct Answer: A

Rationale: Dilated cardiomyopathy results in impaired contractility, leading to heart failure and chamber dilation.

Correct Answer: B

Rationale: Symptoms of RDS typically peak within 24-48 hours, not 7 days. The other statements are true regarding RDS.