A nurse is caring for a newborn who is experiencing hyperbilirubinemia and is receiving phototherapy. Which of the following findings indicate that the phototherapy is effective?

A. Serum bilirubin level has increased from 6 hr ago: An increase in bilirubin suggests that phototherapy is not working effectively or that bilirubin is still accumulating faster than it is being broken down. This finding indicates a need for further assessment or adjustments to therapy. B. Jaundice moves from chest to groin level: Jaundice typically progresses in a cephalocaudal direction. Movement toward the groin reflects worsening hyperbilirubinemia rather than improvement, so this would not indicate effective treatment. C. Hemoglobin and hematocrit have increased: These values are not direct indicators of bilirubin reduction or phototherapy effectiveness. Elevated levels could reflect dehydration or other unrelated factors in a newborn. D. Transcutaneous bilirubin (TCB) level has decreased from 6 hr ago: A decreasing TCB level shows that bilirubin levels are lowering in response to phototherapy. This is the most reliable, noninvasive indicator that the treatment is effective and progressing as intended.