Quick answerNotify the provider now so a bilirubin level is measured right away.
Why this is correctThe detail that decides this item is the hour of life: the face turned yellow at 18 hours. Visible jaundice in the first 24 hours is never assumed to be physiologic, because hemolysis can make bilirubin rise quickly. The good feeding numbers are real but do not explain jaundice this early, so waiting for the routine screen would lose hours.
Easy analogy or mental picturePhysiologic jaundice is a guest who arrives on day 2 or 3; a guest who knocks before the first day is over is not expected, so you check who it is right away.
Memory hookYellow before 24 hours = measure bilirubin NOW. Yellow after 24 hours = check intake and plot against the threshold.
NCLEX decision ruleIn newborn jaundice, look first at the hour of life when jaundice appeared; it decides whether the pathway is urgent measurement or routine follow-up.
Why the other choices are wrongContinuing breastfeeding with a recheck in 2 days is the correct plan for jaundice that appears after 24 hours with a bilirubin below threshold, and the good feeding data make it tempting, but this jaundice appeared at 18 hours. The routine bilirubin screen at 24 hours is correct for a newborn without visible jaundice, yet visible jaundice before 24 hours requires measurement now rather than at the scheduled time. Formula after breastfeeding is appropriate when intake is poor or weight loss is excessive; 9 effective feeds, 3 wet diapers, and 4% weight loss show adequate intake.
References
1MedlinePlus: Newborn jaundiceJaundice that appears in the first 24 hours of life needs prompt evaluation
2StatPearls: Neonatal JaundiceJaundice within 24 hours is considered pathologic until proven otherwise and requires bilirubin measurement