Pregnancies affected by hemolytic disease of the fetus and newborn (HDFN) often require early delivery. Once the fetus reaches a safe gestational age and fetal distress is observed or urgent care that can’t be performed in utero is required, your doctor will likely recommend an earlier delivery. This can either occur via induced labor and a vaginal birth or an elective or emergency cesarean.
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 (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.
How early can a HDFN-affected fetus be induced?
The standard approach in HDFN is to prolong the baby’s time in the womb for as long as possible, to ensure their lungs are fully developed. Fetal lung maturity occurs at around 36 weeks. In general, delivery is recommended at 37 to 38 weeks. If the fetus is in danger, a cesarean can be performed at short notice, at any time.
When planning a premature delivery, the risks of waiting too long include stillbirth and the consequences of severe fetal 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. such as fetalis hydrops. This needs to be balanced against the consequences of prematurity and the risk of severe anemia.
In cases where the fetus has had intrauterine transfusions (IUTIntrauterine transfusion A procedure that delivers donor red blood cells to the fetus through the umbilical vein to treat severe anemia caused by HDFN.) throughout the pregnancy, the final one is usually scheduled at 35 weeks to prepare for a premature delivery.
Learn more about HDFN symptoms and risks
Induction: what to expect
If your doctor recommends induction, it means that your baby is healthy enough to be delivered naturally. HDFN pregnancy and birth is considered high-risk, so a large multidisciplinary team will be on hand throughout labor and the birth of your baby. You will also have a support person or two with you.
Induction means artificially starting contractions by first ‘ripening’ the cervix, separating the membranes of the amniotic sac from the uterus, breaking your water by making a hole in the amniotic sac and if necessary, giving intravenous hormones to bring on contractions. It can take more than 24 hours to progress to active labor, and it may take several days between the start of induction to the birth of your baby.
Be aware that induced labor can often finish in a cesarean and be prepared to be flexible, based on what offers the best outcomes for your baby. Prepare your birth plan, knowing that it won’t necessarily play out exactly as you’d planned.
Post-delivery
On arrival, your preterm newborn will be transferred to the neonatal intensive care unit (NICU) for specialized treatment for anemia 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.. This may include breathing assistance, phototherapyPhototherapy A treatment that uses special blue light to help newborns break down bilirubin and prevent kernicterus. for jaundice and blood transfusions for anemia.
