HDN may develop when a mother and her unborn baby have different blood types (called "incompatibility"). The mother produces substances called antibodies that attack the developing baby's red blood cells.
The most common form of HDN is ABO incompatibility, which is usually not very severe. Other, less common types may cause more severe problems.
The least common form is Rh incompatibility, which can almost always be prevented. When this form does occur, it can cause very severe anemia in the baby.
HDN can destroy the newborn baby's blood cells very quickly, which can cause symptoms such as:
Drugs used to treat allergic reactions (antihistamines)
Drugs used to treat swelling and allergies (steroids)
Feeding and fluids (hydration)
Fluids given through a vein (intravenously)
Light therapy using bilirubin lights
Medicines to raise blood pressure if it drops too low
The severity of this condition can vary. Some babies have no symptoms. In other cases, problems such as hydrops can cause the baby to die before, or shortly after birth. Severe HDN may be treated before birth by intrauterine blood transfusion.
The most severe form of this disease, which is caused by Rh incompatibility, can be prevented if the mother is given a shot of a medicine called RhoGAM at certain times during and after her pregnancy. If you have had a baby with this disease, talk with your doctor if you plan to have another baby.
Gruslin AM, Moore TR. Erythroblastosis fetalis. In: Martin R, Fanaroff A, Walsh M, eds. Neonatal-Perinatal Medicine. 9th ed. Philadelphia, Pa: Mosby Elsevier; 2011.
Cohen DW. Hemolytic disease of the newborn: RBC alloantibodies in pregnancy and associated serologic issues. UpToDate [online]. Waltham, Ma: Nov 2009.
Kimberly G Lee, MD, MSc, IBCLC, Associate Professor of Pediatrics, Division of Neonatology, Medical University of South Carolina, Charleston, SC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.