ABO incompatibility jaundice is a unique form of jaundice. This condition can show up if a mother has type O blood and her baby has A, B, or AB type blood. During pregnancy a mother may produce antibodies against the baby’s blood type. These antibodies can pass through the placenta to the baby and cause the baby to start to break down extra red blood cells even before he’s born. The result may be a quick onset of jaundice in the newborn. If the level of bilirubin rises too quickly in the first 24 hours after birth, the pediatrician will place the newborn under phototherapy. This will not affect breastfeeding. In extreme situations when the baby gets a very high bilirubin level, the baby may require a blood transfusion.