A 3-day-old male infant, born at 39 weeks via normal vaginal delivery, is noted by the midwife to appear jaundiced. The baby is breastfeeding well, has passed urine and meconium, and is otherwise alert with normal observations. There is no history of maternal infection or complications during pregnancy. On examination, the infant has yellow discolouration of the skin up to the thighs. No hepatosplenomegaly or dysmorphic features are noted.