What immediate intervention should be taken for a newborn with suspected jaundice?

In the context of a newborn with suspected jaundice, the immediate intervention that is most appropriate is to perform a blood test for bilirubin levels. This step is crucial because it allows healthcare providers to assess the severity of jaundice. Jaundice in newborns is usually caused by an accumulation of bilirubin, a yellow pigment formed during the breakdown of red blood cells.

Measuring the bilirubin levels helps determine if treatment is necessary and what type of treatment may be required. Early identification of elevated bilirubin levels can help prevent potential complications, such as kernicterus, which is a serious neurological condition that can arise from untreated high bilirubin levels.

While phototherapy may be necessary depending on the bilirubin results, it is not the immediate first step; instead, it is a treatment that follows the assessment based on bilirubin testing. Similarly, monitoring blood glucose levels or feeding the baby formula may be relevant in different clinical situations, but they do not directly address the evaluation of jaundice itself.