Final answer:
The baby is admitted to the nursery due to jaundice caused by ABO incompatibility.
Step-by-step explanation:
The reason for the baby's admission to the nursery is jaundice due to ABO incompatibility. ABO incompatibility occurs when the mother's blood type and the baby's blood type are not compatible. When the baby's blood type (typically A or B) is different from the mother's blood type (typically O), there can be an immune response that leads to the destruction of the baby's red blood cells.
This destruction of red blood cells can cause an increase in bilirubin levels in the baby's blood, leading to jaundice. Jaundice is a yellowing of the skin and eyes due to elevated bilirubin levels. To treat the jaundice, the baby may need phototherapy or, in severe cases, a blood transfusion.