Newborns diagnosed with hemolytic disease of the fetus and newborn (HDFN) commonly experience both hyperbilirubinemia and what is known as rebound hyperbilirubinemia.
To avoid serious long-term consequences, treatment by phototherapy and blood transfusions is usually required. In the 24 hours following the end of phototherapy, a doctor will likely order a blood test to measure bilirubin levels in the blood. If the levels are elevated, this indicates rebound hyperbilirubinemia, and treatment will need to be reinitiated.
What is HDFN?
Hemolytic disease of the fetus and newborn (HDFN) is an immune-mediated red blood cell disorder that occurs when a baby’s RBCs break down quickly, which is called hemolysis. HDFN is caused by a mismatch between a mother’s and her baby’s blood type (A, B, AB, or O) or Rhesus (Rh) factor (Rh-positive or Rh-negative) during pregnancy.
What is hyperbilirubinemia?
Hyperbilirubinemia, also known as jaundice, is common in newborns with HDFN. Bilirubin is a yellowish substance that occurs as a byproduct of red blood cells breaking down. Newborns have difficulty eliminating it from their systems and it accumulates, causing symptoms such as yellow skin, whites of the eyes and gums, dark colored urine, pale stools, sleepiness, fussiness and poor feeding.
Learn more about HDFN symptoms and risks
If left untreated, the bilirubin can cross the blood-brain barrier causing a complication called kernicterus. This can result in permanent hearing loss, cerebral palsy and brain damage. Treatment with phototherapy to reduce bilirubin levels usually has successful outcomes.
What is rebound hyperbilirubinemia?
Once bilirubin levels have been reduced and stabilized, phototherapy will be stopped. However, close monitoring will be required over the next 24 hours. Rebound hyperbilirubinemia or rebound jaundice refers to bilirubin levels returning to elevated levels and requiring the re-initiation of treatment. It can occur 18 to 24 hours after phototherapy has been stopped. Bilirubin levels will be monitored with a blood test within the 24 hours after treatment has finished.
Why does rebound hyperbilirubinemia occur in HDFN?
Rebound hyperbilirubinemia affects up to 10% of newborns. Newborns with risk factors such as HDFN, prematurity and low birth weight are more likely to experience rebound hyperbilirubinemia. It occurs because the breakdown of red blood cells as a result of maternal antibodies can continue for the first days or weeks of life, creating more bilirubin in the blood. Additionally, the newborn’s liver is immature and therefore has difficulty processing the bilirubin to eliminate it in their stool and urine.
When rebound hyperbilirubinemia is detected, immediate reinitiation of phototherapy is recommended. In some cases, hyperbilirubinemia can return more than once. According to one study, 20.3% of treated cases of jaundice experienced one episode of rebound hyperbilirubinemia and 3.9% experienced two episodes.
Sign up here to get the latest news, perspectives, and information about HDFN sent directly to your inbox. Registration is free and only takes a minute.
