Hemolytic Disease of the Newborn (HDN)

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
called erythroblastosis fetalis. 

  • Hemolytic means breaking down of red
    blood cells.
  • Erythroblastosis means making immature
    red blood cells.
  • Fetalis means fetus.

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
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
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
prenatal test. These can include amniocentesis or chorionic villus sampling. These
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
fight the Rh positive cells in the baby’s body. As the antibodies destroy the cells,
baby gets sick. This is called erythroblastosis fetalis during pregnancy. Once the
is born, it’s called 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.

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

  • 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

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
    36 hours.  
  • Your newborn may have a big liver and
  • A newborn with hydrops
    fetalis may have severe swelling of their entire body. They may also be very pale
    have trouble breathing.

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
    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
    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
  • Testing of the baby’s blood for
    bilirubin levels.

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.

Early delivery

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 getting worse.

After birth, treatment may
include the following.

Blood transfusions

This may be done if your baby
has severe anemia.

Intravenous fluids

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.

Exchange transfusion

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.

When your antibodies attack your baby’s red blood cells, they are
broken down and destroyed (hemolysis).

When your baby’s red blood cells
break down, bilirubin is formed. It’s hard for babies to get rid of bilirubin. It
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

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
can’t do the work of mature red blood cells.

Complications of HDN can be mild or

During pregnancy, your baby may
have the following:

  • Mild anemia, hyperbilirubinemia, and
    The placenta gets rid of some bilirubin. But it can’t remove all of
  • Severe anemia. This can cause your
    baby’s liver and spleen to get too big. This can also affect other organs.
  • Hydrops fetalis. This happens when
    your baby’s organs aren’t able to handle the anemia. Your baby’s heart will start
    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

  • Severe hyperbilirubinemia and
    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

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

  • 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
  • When the antibodies enter the baby’s
    blood, they will attack the red blood cells. This causes them to break down. This
    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
  • 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.