**ABO blood type differences do not go away, but mild effects in your newborn can resolve without treatment.**
During pregnancy, your antibodies can cross the placenta and break down your baby's red blood cells, causing jaundice or anemia. These antibodies gradually clear after birth, but your baby's bilirubin level and blood count determine whether treatment is needed. Your clinician may recommend monitoring, special light treatment called phototherapy, or treatment for anemia. Feed your baby regularly and keep every recommended follow-up appointment. If you mean an ABO reaction from a blood transfusion, you need immediate medical care.
How it resolves
Common questions
Can ABO incompatibility go away on its own?
ABO incompatibility means blood types are incompatible; that difference does not disappear. In your newborn, mild jaundice from maternal antibodies can resolve as those antibodies clear after birth. Your baby's clinician must check bilirubin and assess for anemia before deciding that observation is enough. Some babies need phototherapy or a transfusion. Feed regularly and keep scheduled checks; sunlight is not a treatment. Seek urgent care for jaundice in the first 24 hours, poor feeding, or difficulty waking. An ABO transfusion reaction needs immediate medical treatment.