What is commonly the first clinical sign of coarctation of the aorta in neonates?

The first clinical sign of coarctation of the aorta in neonates is often decreased blood pressure in the lower extremities. In this condition, there is a narrowing of the aorta, typically just below the left subclavian artery, which leads to differential blood flow. Because the area before the coarctation receives adequate blood supply, the upper body usually maintains normal or elevated blood pressure. In contrast, the lower body experiences diminished blood flow due to the obstruction, resulting in significantly lower blood pressure readings in the legs compared to the arms.

This differential blood pressure is critical for diagnosing coarctation of the aorta in neonates. Early detection is essential because coarctation can lead to significant morbidity and mortality if not addressed promptly. Monitoring blood pressure in all four limbs is a common practice in neonatal assessments to identify this condition early on.

The other options, while symptoms that may present in a broader context of cardiac issues, are not specific indicators of coarctation of the aorta. Failure to thrive often reflects a longer-term issue with feeding or metabolic problems and is not an immediate sign. Increased heart rate can occur in many other conditions, particularly if there is a compromised circulation. Respiratory distress is a nons