Women with high-risk pregnancies are generally advised against home births, as they can involve a greater risk for maternal and neonatal morbidity and mortality. Pregnancies in women at risk of hemolytic disease of the fetus and newborn (HDFN) are classified as high-risk and require specialized care throughout pregnancy and birth.
Early delivery by cesarean can sometimes be advised in emergencies and newborns with HDFN will require expert medical care.
What is HDFN?
Hemolytic disease of the fetus and newborn (HDFN) is an immune-mediated red blood cell (RBC) 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 (RhRh factor A protein or antigen found on red blood cells. When an Rh-negative mother carries an Rh-positive fetus, her immune system may make antibodies that attack the fetus' red blood cells.) factor (Rh-positiveRh-Positive A blood type trait that means your red blood cells have the Rh(D) antigen. or Rh-negativeRh-Negative A blood type trait that means your red blood cells lack the Rh(D) antigen.) during pregnancy. Numerous antibodiesAntibody A protein made by the immune system that recognizes and attacks foreign substances, such as bacteria, or in HDFN, fetal red blood cells carrying incompatible antigens. to RBC antigensAntibody A protein made by the immune system that recognizes and attacks foreign substances, such as bacteria, or in HDFN, fetal red blood cells carrying incompatible antigens. can be linked to HDFN, such as those from the ABO and Rh blood groupBlood group A classification of blood based on inherited markers found on red blood cells. The ABO and Rh blood groups are most common in HDFN. systems.
Pregnancy and birth in mothers at risk of HDFN
HDFN can occur late in pregnancy or be triggered during birth if the baby’s blood comes into contact with the mother’s blood, causing alloimmunizationAlloimmunization When a person’s immune system develops antibodies against foreign antigens from the same species—such as when an Rh-negative mother’s body forms antibodies against her baby’s Rh-positive red blood cells. of the maternal blood.
Prenatal screening will detect the risk of HDFN in a pregnant mother, and in most cases, she will be referred to a specialist with facilities for fetal diagnosis, intrauterine transfusion and high-dependency newborn care. This contributes to improved outcomes for the mother and baby.
Some pregnancies are classified as being ‘at-risk’ of HDFN, which means that the pregnant mother is Rh-negative, and her baby is most likely Rh-positive, but she hasn’t yet developed antibodies to her baby’s red blood cells. The pregnant mother will likely receive Rh(D) immunoglobulinIntravenous immunoglobulin A therapy made from donated antibodies that may help reduce the mother’s immune response and protect the fetus. to prevent HDFN, but is not always 100% effective.
Births in at-risk mothers can require urgent medical intervention that influences the survival of the baby. Following birth, HDFN can be diagnosed in newborns by testing the umbilical cord blood to see if the mother’s antibodies are present. Immediate treatment can minimize the long-term effects of HDFN on the newborn. The severity of HDFN complications in newborns can vary from mild anemiaAnemia A condition that occurs when the body doesn’t have enough healthy red blood cells to carry oxygen to its tissues. In HDFN, anemia occurs when maternal antibodies destroy fetal red blood cells. and jaundiceJaundice A common symptom of HDFN, jaundice is caused by excess bilirubin and is characterized by a yellow tint to the skin or eyes. to brain damage and hearing loss. In some rare cases, HDFN can result in the death of an infant.
Risks of home births for those at risk of HDFN
Home births are often supervised by midwives, rather than obstetricians or maternal-fetal specialists, which are recommended to care for mother and baby during pregnancies at risk of HDFN. Doulas can also assist, to provide support to the mother and family. In a low-risk context, a home birth can be a positive experience. However, if complications occur, life-saving medical facilities are not as easily accessible, creating an additional risk.
According to the American College of Obstetricians and Gynecologists’ Committee on Obstetric Practice, home births have a twofold risk of perinatal death and a threefold increased risk of neonatal seizures or serious neurologic dysfunction. In the case of pregnancies with the potential for HDFN, the baby is already at risk of complications. The risk for the baby is therefore amplified in a home birth setting, and immediate care is not available, increasing the possibility of short and long-term complications for the infant.
