Hemolytic Disease of the Newborn (HDN)
What is hemolytic disease of the newborn?
Hemolytic disease of the newborn (HDN) is a blood problem in newborn babies. It occurs
when your baby's red blood cells break down at a fast rate. It’s also called erythroblastosis
What causes HDN in a newborn?
All people have a blood type (A, B, AB, or O). Everyone also has an Rh factor (positive
or negative). There can be a problem if a mother and baby have a different blood type
and Rh factor.
HDN happens most often when an Rh negative mother has a baby with an Rh positive father. If the
baby's Rh factor is positive, like their father's, this can be an issue if the baby's
red blood cells cross to the Rh negative mother.
This often happens at birth when the placenta breaks away. But it may also happen
any time the mother’s and baby's blood cells mix. This can occur during a miscarriage
or fall. It may also happen during a prenatal test. These can include amniocentesis
or chorionic villus sampling. These tests use a needle to take a sample of tissue.
They may cause bleeding.
The Rh negative mother’s immune system sees the baby's Rh positive red blood cells
as foreign. Your immune system responds by making antibodies to fight and destroy
these foreign cells. Your immune system stores these antibodies in case these foreign
cells come back again. This can happen in a future pregnancy. You are now Rh sensitized.
Rh sensitization normally isn’t a problem with a first pregnancy. Most problems occur in
future pregnancies with another Rh positive baby. During that pregnancy, the mother's
antibodies cross the placenta to fight the Rh positive cells in the baby's body. As
the antibodies destroy the cells, the baby gets sick. This is called erythroblastosis
fetalis during pregnancy. Once the baby is born, it’s called HDN.
Which children are at risk for HDN?
The following can raise your risk for having a baby with HDN:
You’re Rh negative and have an Rh positive baby but haven’t received treatment.
You’re Rh negative and have been sensitized. This can happen in a past pregnancy with
an Rh positive baby. Or it can happen because of an injury or test in this pregnancy
with an Rh positive baby.
HDN is about 3 times more common in white babies than in African-American babies.
What are the symptoms of HDN in a newborn?
Symptoms can occur a bit differently in each pregnancy and child.
During pregnancy, you won't notice any symptoms. But your healthcare provider may
see the following during a prenatal test:
A yellow coloring of amniotic fluid. This color may be because of bilirubin. This
is a substance that forms as blood cells break down.
Your baby may have a big liver, spleen, or heart. There may also be extra fluid in
their stomach, lungs, or scalp. These are signs of hydrops fetalis. This condition
causes severe swelling (edema).
After birth, symptoms in your baby may include:
Pale-looking skin. This is from having too few red blood cells (anemia).
Yellow coloring of your baby’s umbilical cord, skin, and the whites of their eyes
(jaundice). Your baby may not look yellow right after birth. But jaundice can come
on quickly. It often starts in 24 to 36 hours.
Your newborn may have a big liver and spleen.
A newborn with hydrops fetalis may have severe swelling of their entire body. They
may also be very pale and have trouble breathing.
How is HDN diagnosed in a newborn?
HDN can cause symptoms similar to those caused by other conditions. To make a diagnosis,
your child’s healthcare provider will look for blood types that cannot work together.
Sometimes this diagnosis is made during pregnancy. It will be based on results from
the following tests:
Blood test. Testing is done to look for Rh positive antibodies in your blood.
Ultrasound. This test can show enlarged organs or fluid buildup in your baby.
Amniocentesis. This test is done to check the amount of bilirubin in the amniotic fluid. In this
test, a needle is put into your abdominal and uterine wall. It goes through to the
amniotic sac. The needle takes a sample of amniotic fluid.
Percutaneous umbilical cord blood sampling. This test is also called fetal blood sampling. In this test, a blood sample is taken
from your baby’s umbilical cord. Your child’s healthcare provider will check this
blood for antibodies, bilirubin, and anemia. This is done to check if your baby needs
an intrauterine blood transfusion.
The following tests are used to diagnose HDN after your baby is born:
Testing of your baby's umbilical cord. This can show your baby’s blood group, Rh factor,
red blood cell count, and antibodies.
Testing of the baby's blood for bilirubin levels.
How is HDN treated in a newborn?
During pregnancy, treatment for HDN may include the following.
A healthcare provider will check your baby’s blood flow with an ultrasound.
Intrauterine blood transfusion
This test puts red blood cells into your baby's circulation. In this test, a needle
is placed through your uterus. It goes into your baby’s abdominal cavity to a vein
in the umbilical cord. Your baby may need sedative medicine to keep him or her from
moving. You may need to have more than 1 transfusion.
If your baby gets certain complications, they may need to be born early. Your healthcare
provider may induce labor may once your baby has mature lungs. This can keep HDN from
After birth, treatment may include the following.
This may be done if your baby has severe anemia.
This may be done if your baby has low blood pressure.
In this test, your baby is put under a special light. This helps your baby get rid
of extra bilirubin.
Help with breathing
Your baby may need oxygen, a substance in the lungs that helps keep the tiny air sacs
open (surfactant), or a mechanical breathing machine (ventilator) to breathe better.
This test removes your baby’s blood that has a high bilirubin level. It replaces it
with fresh blood that has a normal bilirubin level. This raises your baby’s red blood
cell count. It also lowers their bilirubin level. In this test, your baby will alternate
giving and getting small amounts of blood. This will be done through a vein or artery.
Your baby may need to have this procedure again if their bilirubin levels stay high.
Intravenous immunoglobulin (IVIG)
IVIG is a solution made from blood plasma. It contains antibodies to help the baby's
immune system. IVIG reduces your baby’s breakdown of red blood cells. It may also
lower their bilirubin levels.
What are possible complications of HDN in a newborn?
When your antibodies attack your baby’s red blood cells, they are broken down and
When your baby’s red blood cells break down, bilirubin is formed. It’s hard for babies
to get rid of bilirubin. It can build up in their blood, tissues, and fluids. This
is called hyperbilirubinemia. Bilirubin makes a baby’s skin, eyes, and other tissues
to turn yellow. This is called jaundice.
When red blood cells breakdown, this makes your baby anemic. Anemia is dangerous.
In anemia, your baby’s blood makes more red blood cells very quickly. This happens
in the bone marrow, liver, and spleen. This causes these organs to get bigger. The
new red blood cells are often immature and can’t do the work of mature red blood cells.
Complications of HDN can be mild or severe.
During pregnancy, your baby may have the following:
Mild anemia, hyperbilirubinemia, and jaundice. The placenta gets rid of some bilirubin. But it can’t remove all of it.
Severe anemia. This can cause your baby’s liver and spleen to get too big. This can also affect
Hydrops fetalis. This happens when your baby's organs aren’t able to handle the anemia. Your baby’s
heart will start to fail. This will cause large amounts of fluid buildup in your baby's
tissues and organs. Babies with this condition are at risk for being stillborn.
After birth, your baby may have the following:
Severe hyperbilirubinemia and jaundice. Your baby’s liver can’t handle the large amount of bilirubin. This causes your baby’s
liver to grow too big. They will still have anemia.
Kernicterus. This is the most severe form of hyperbilirubinemia. It’s because of the buildup of
bilirubin in your baby’s brain. This can cause seizures, brain damage, and deafness.
It can even cause death.
What can I do to prevent hemolytic disease of the newborn?
HDN can be prevented. Almost all women will have a blood test to learn their blood
type early in pregnancy.
If you’re Rh negative and have not been sensitized, you’ll get a medicine called Rh
immunoglobulin (RhoGAM). This medicine can stop your antibodies from reacting to your
baby’s Rh positive cells. Many women get RhoGAM around week 28 of pregnancy.
If your baby is Rh positive, you’ll get a second dose of medicine within 72 hours
of giving birth. If your baby is Rh negative, you won’t need a second dose
Key points about hemolytic disease of the newborn
HDN occurs when your baby's red blood cells break down at a fast rate.
HDN happens when an Rh negative mother has a baby with an Rh positive father.
If the Rh negative mother has been sensitized to Rh positive blood, her immune system
will make antibodies to attack her baby.
When the antibodies enter the baby's blood, they will attack the red blood cells.
This causes them to break down. This can cause problems.
This condition can be prevented. Women who are Rh negative and haven’t been sensitized
can receive medicine. This medicine can stop your antibodies from reacting to your
baby’s Rh positive cells.
Tips to help you get the most from a visit to your child’s healthcare provider:
Know the reason for the visit and what you want to happen.
Before your visit, write down questions you want answered.
At the visit, write down the name of a new diagnosis, and any new medicines, treatments,
or tests. Also write down any new instructions your provider gives you for your child.
Know why a new medicine or treatment is prescribed and how it will help your child.
Also know what the side effects are.
Ask if your child’s condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
Know what to expect if your child does not take the medicine or have the test or procedure.
If your child has a follow-up appointment, write down the date, time, and purpose
for that visit.
Know how you can contact your child’s provider after office hours. This is important
if your child becomes ill and you have questions or need advice.