Hemolytic Disease of the Fetus and Newborn
A clear guide for families navigating an at-risk pregnancy
Our goal
Understand your risk, your baby’s monitoring, and how specialists prevent or treat anemia before and after birth.
What is HDFN?
Maternal antibodies can cross the placenta and remove fetal red blood cells. This may cause anemia before birth and jaundice after birth.
How antibodies form
Exposure to unfamiliar red-cell antigens may occur during pregnancy, birth, bleeding, procedures, or transfusion. Your immune system can remember that antigen.
A positive screen is a starting point
A positive antibody screen does not mean your baby is anemic. The next steps identify the antibody and whether your baby carries its target antigen.
Some antibodies need closer attention
Anti-D, anti-c, and anti-Kell can cause important fetal or newborn disease. Many other antibodies cause little or no fetal harm.
Screening finds the signal
Early prenatal testing checks your blood type and red-cell antibodies. If positive, the laboratory identifies the antibody and measures its level.
Is your baby susceptible?
Targeted cell-free fetal DNA may identify your baby’s red-cell antigen after 10 weeks. If the antigen is absent, that antibody cannot attack fetal cells.
History and titers guide monitoring
Prior affected pregnancies increase risk. Rising or critical titers prompt fetal surveillance. Thresholds vary by antibody and laboratory; anti-Kell is managed differently.
MCA Doppler: a painless screening test
Ultrasound measures blood speed in a fetal brain artery. Faster flow can signal anemia. The test does not expose your baby to radiation.
Interpreting the Doppler
Below 1.5 MoM is generally reassuring. At or above 1.5 MoM raises concern for moderate-to-severe anemia and requires specialist evaluation.
The clinical pathway
When anemia is suspected
Your care team may recommend fetal blood sampling at a fetal therapy center. The same procedure can confirm anemia and immediately deliver compatible blood.
Intrauterine transfusion
Ultrasound guides a needle into the umbilical vein. Compatible red cells treat fetal anemia. Some babies need repeat transfusions before planned delivery.
Your high-risk care team
Maternal-fetal medicine, fetal therapy, transfusion medicine, obstetrics, and neonatology coordinate surveillance, blood availability, delivery timing, and newborn care.
Delivery is planned, not automatic
Many stable pregnancies reach early term. Earlier delivery may be safer if anemia worsens, monitoring changes, transfusion is unsuitable, or another obstetric concern develops.
Your baby’s first checks
After birth, clinicians assess breathing, color, blood type, antibodies, hemoglobin, and bilirubin. Results determine nursery care, NICU observation, and treatment.
Treatments are tailored
Phototherapy treats jaundice. Transfusion treats anemia. Exchange transfusion is reserved for dangerous bilirubin levels. IVIG has selective use when bilirubin rises despite intensive phototherapy.
Follow-up still matters
Bilirubin can rebound, and anemia may appear later. Keep newborn appointments and obtain recommended blood tests, even when your baby looks well.
Rh immune globulin prevents anti-D
Rh immune globulin helps unsensitized RhD-negative patients avoid anti-D antibodies. It does not remove existing anti-D or prevent antibodies against other antigens.
What you can do
Keep appointments. Share prior pregnancy and transfusion records. Ask which antibody you have, whether your baby is susceptible, and what changes require urgent contact.
Reasons for confidence
Most at-risk pregnancies are identified before severe illness. Surveillance can detect anemia early, and specialized fetal and newborn treatments are available when needed.
Ask your care team
Use this guide with your care team
This presentation provides general education and does not replace medical advice, diagnosis, or treatment from your own clinicians. Your antibody, pregnancy history, laboratory results, ultrasound findings, and local resources determine your individual plan.
Professional guidance
Updated evidence + patient resources
You are not facing this alone
Monitoring creates time to act. Your team will tailor every decision to you and your baby.