Sharing information today to save the lives of tomorrow.
Isoimmunization: An Intro to Antibodies in Pregnancy
Empowering women to be partners in their prenatal care.
Sharing information today to save the lives of tomorrow.
Sharing information today to save the lives of tomorrow.
After Birth Blood Testing – All About Baby
You made it! On this page, you will find things to keep in mind for after you've delivered an ISO baby. If you haven't already, it is helpful to keep a notebook and write down all your questions (and the doctor's answers) about birth and the hospital's processes. Also, make sure they will have antigen negative blood ready for baby. If you've got anti-Kell, baby needs Kell negative blood. If he needs a transfusion, you don't want to wait several hours and risk brain damage while they find blood. Don't forget to pop over to the Printables page to help you keep track of all the test results. There's even a copy of all the referenced normal laboratory values. You'll also find the pages on complications and interventions helpful.
After Birth Blood Testing - All About Baby
Direct Coombs Test
Hemoglobin
Hematocrit
Ferritin
Reticulocyte Count
Bilirubin Test
Neutrophil Count
Platelet/Thrombocyte Count
Newborn Blood Screening
Note: If your baby has had IUTs, the state required newborn blood screening may be off (it may be testing donor blood and not baby’s blood), and should be repeated at 1 year of age.
These photos are all of umbilical lines. These lines may be put in to get accurate draws and IVs if necessary. These can be an alternative to heel sticks for testing.
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This baby also has swelling from an enlarged liver. -
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Direct Coombs test (DAT)
What is it?
Also called the Direct Antiglobulin Test (DAT)
The direct antiglobulin test (DAT) is performed to determine whether an anemic patient with evidence of hemolysis has isoimmune hemolytic anemia. If baby has a positive direct coombs test, there are antibodies already bound to and attacking the red blood cells. These antibodies can be removed from the RBC and each specific antibody can be identified. While the indirect coombs test shows if Mom is making antibodies and has them floating around loose in her blood, the direct coombs test shows if the antibodies are present in the baby’s blood and bound to the red blood cells. (22)
When is it done?
This test should be run at birth.
Where is it done?
This test will usually be done in the hospital.
Why is it done?
This test is done to see if there are any of mom's antibodies bound to and attacking the baby's blood.
How is it done?
This test can be done by taking blood from the umbilical cord or through a heel stick.
How often is it done?
For iso babies, this test is usually only performed once at birth.
What do the results mean?
A negative Direct Coombs means that there are not antibodies bound to the baby's blood.
A positive Direct Coombs means that there are antibodies attacking the baby's blood. A positive result will mean that your baby needs additional testing and monitoring.
Additional Information
Occasionally, especially with IUTs, the baby may have a negative direct coombs. In this case, an indirect coombs may be run to see if there are antibodies in the blood that aren't bound and attacking the cells. Indirect coombs should also be run in the case of anti-C/anti-c.
Hemoglobin
What is it?
Hemoglobin is a protein in red blood cells that carries oxygen. A blood test can tell how much hemoglobin you have in your blood.23 It is usually abbreviated Hb or Hgb and is measured in grams per deciliter. It is usually done as part of a complete blood count (CBC).
When is it done?
Hemoglobin should be tested at birth, and frequently thereafter.
Where is it done?
This test is usually done in the hospital or at a laboratory.
Why is it done?
Hemoglobin is checked to make sure that the baby is not anemic.
How is it done?
This test can be done by taking blood from the umbilical cord or through a heel stick.
How often is it done?
How often hemoglobin is checked depends on each case. Usually it is checked every 1-2 days in the hospital, or if baby is showing symptoms of being anemic. If baby's Hgb is dropping, more frequent checks will be needed. As baby gets older, less frequent checks are usually needed. Because ISO babies are at risk for developing late onset anemia, hemoglobin levels should be checked until at the baby is at least 12 weeks old.
What do the results mean?
Selected Normal Pediatric Laboratory Values – Hemoglobin (24)
The calculated minimum acceptable hemoglobin concentration is 6 g/dl for children and adults, 12 g/dl for preterm infants and 11 g/dl for full-term neonates at birth. The minimum hemoglobin concentration should be 2 g/dl higher in patients who require increased oxygen or suffer from other serious disorders. Because of how the baby deals with oxygen, the minimum value of 12 g/dl or 11g/dl decreases by approximately 1 g/dl each week for 5 or 6 weeks until the minimum of 6g/dl for children and adults is reached. (25)
If numbers are high
If the hemoglobin is above 10 g/dL (in the absence of specific risk factors related to the patient’s clinical characteristics) there is no need to transfuse red blood cells. Hemoglobin should still be checked regularly.
If numbers are low
Depending on how low the numbers are, treatment may be non urgent or urgent. If non-urgent, the baby will be monitored to see if he will start to make his own blood cells and recover from anemia on his own. If treatment is urgent, a blood transfusion will be performed.
Subjects with Hb concentrations below 6 g/dL almost always require transfusion therapy. In stabilized patients with Hb values between 6 and 10 g/dL, the decision whether to transfuse is based on an evaluation of clinical status; patients with values above 10 g/dL rarely require transfusion.
Indications for transfusion: Hemoglobin concentration of 4 g/dL or less (or hematocrit 12%), whatever the clinical condition of the patient or Hemoglobin concentration of 4-6 g/dl (or hematocrit 13-18%) if any the following clinical features are present: Clinical features of hypoxia, Acidosis (usually causes dyspnoea), Impaired consciousness (27).
Additional Information
You should be wary of giving your ISO baby iron supplements. Most ISO babies have normal or high iron levels and serious damage or death can occur if they are given iron supplements. Unless the Ferritin level is specifically tested, DO NOT GIVE IRON.
IRON IS NOT AN ACCEPTABLE TREATMENT FOR AN ISO BABY (47). The anemia faced by an iso baby is caused by red blood cell destruction, not iron deficiency. Many iso babies have normal or even high levels of iron and can be easily overdosed and killed from supplements. Your baby should never be given iron supplements without having his ferritin levels checked. Normal Ferritin levels are 25-200 ng/mL (46).
Hematocrit
What is it?
Hematocrit is a blood test that measures the percentage of the volume of whole blood that is made up of red blood cells28. It is abbreviated HCT or Htc, and may be done as part of a complete blood count (CBC).
When is it done?
Hematocrit should be tested at birth, and frequently thereafter.
Where is it done?
This test is usually done in the hospital or at a laboratory.
Why is it done?
Hematocrit is checked to make sure that the baby is not anemic.
How is it done?
This test can be done by taking blood from the umbilical cord or through a heel stick.
How often is it done?
How often hematocrit is checked depends on each case. Usually it is checked every 1-2 days in the hospital, or if baby is showing symptoms of being anemic. If baby's hematocrit is dropping, more frequent checks will be needed. As baby gets older, less frequent checks are usually needed. Because ISO babies are at risk for developing late onset anemia, hematocrit levels should be checked until at the baby is at least 12 weeks old.
What do the results mean?
Selected Normal Pediatric Laboratory Values - Hematocrit (24)
If numbers are high
Great, a transfusion may not be needed, but the hematocrit levels should still be checked regularly until at least 12 weeks of age. It should also be remembered that patients with acute hemorrhage can have normal, or even high, Htc values until the plasma volume is restored; the clinical evaluation of the patient in this situation is, therefore, extremely important (26).
If numbers are low
Depending on how low the numbers are, treatment may be non-urgent or urgent. If non-urgent, the baby will be monitored to see if he will start to make his own blood cells and recover from anemia on his own. If treatment is urgent, a blood transfusion will be performed.
Indications for transfusion: Hematocrit 12%, whatever the clinical condition of the patient or Hematocrit 13-18% if any the following clinical features are present: Clinical features of hypoxia, Acidosis (usually causes dyspnoea), Impaired consciousness (27). Some doctors will transfuse at 20-25% for symptomatic anemia, while others will transfuse at 20% for asymptomatic anemia (29).
After transfusion, the hematocrit goal will be >25% for anemia with symptoms, and >20% for anemia without symptoms.
Ferritin
What is it?
Ferritin is a protein in that carries iron. Most of the body’s iron is bound to ferritin. A blood test can tell how much ferritin you have in your blood. A high ferritin level means baby may be in danger of an iron overdose. Most iso babies have a normal or high ferritin level depending on if they had IUTs. IUTs are done with adult blood cells that are very rich in ferritin. It is very important even if baby has not had a transfusion that you not give iron supplements or vitamins with iron in them until you have the ferritin level tested.
When is it done?
Ferritin is tested at request. It is not part of a normal blood draw unless the provider is looking for additional causes of anemia.
Where is it done?
This test is usually done in the hospital or at a laboratory.
Why is it done?
Ferritin is checked to find out the baby’s iron levels and to rule out iron deficiency anemia.
How is it done?
This test can be done by taking blood from the umbilical cord, or through a vein.
How often is it done?
How often ferritin is checked depends on each case. Most of the time the doctor will only draw it once unless the levels are really high.
What do the results mean?
Selected Normal Pediatric Laboratory Values – Ferritin (46)
If numbers are high
High ferritin levels (over 1,000 ng/mL) can mean a large buildup of iron in the body. With iso babies, this is usually called acquired hemochromatosis, and can be caused by multiple transfusions. Too much iron in the body’s organs can affect how the organ works.
If numbers are low
Low ferritin levels generally mean that anemia is iron deficiency anemia and can be helped with iron supplements.
Additional Information
You should be wary of giving your ISO baby iron supplements. Most ISO babies have normal or high iron levels and serious damage or death can occur if they are given iron supplements. Unless the Ferrin level is specifically tested, it is best to avoid them. It is especially important to avoid them until the transfusion window has closed. You will also want to check on the amount of iron in formula if you formula feed. Try to choose a no or low iron formula.
Reticulocyte Count (Retic)
What is it?
A reticulocyte count (retic) is a blood test that measures how fast specific red blood cells (RBCs), called reticulocytes, are being made by the bone marrow and released into the blood. (30)
When is it done?
Retic should be tested at birth, and frequently thereafter.
Where is it done?
This test is usually done in the hospital or at a laboratory.
Why is it done?
This test is done to see how well the bone marrow is working at making red blood cells and to check to see if treatment for anemia is working. For example, a higher reticulocyte count means that treatment to reverse the anemia is working. (30)
How is it done?
This test can be done by taking blood from the umbilical cord or through a heel stick.
How often is it done?
How often retic is checked depends on each case. Usually it is checked every 1-2 days in the hospital, or if baby is showing symptoms of being anemic. If baby's retic is dropping, or not increasing properly, more frequent checks may be needed. As baby gets older, less frequent checks are usually needed.
What do the results mean?
The retic is given as the percentage of RBCs that are reticulocytes. The normal range can vary from lab to lab, but this is a general guide. Newborns have a normal reticulocyte count of 2.5% to 6.5%. In normal babies, this value drops within 2 weeks to 0.5% to 2.0%. (30) In ISO babies, it is normal for the retic to remain higher for longer as the baby combats anemia.
If numbers are high
A high retic means more red blood cells are being made by the bone marrow.
If numbers are low
A low retic means that fewer RBCs are being made. Retic can be low after baby has had an IUT. It is actually beneficial for babies to have a retic of 0 at certain times. This is when you have replaced the baby's blood with donor blood, and do not want the baby making any more of his own blood cells until after he is delivered and can have an exchange transfusion to get rid of the antibodies. If there are none of the baby's blood cells, then there is nothing for the mother's antibodies to attack. It can take a while for babies to begin to make their own red blood cells after delivery, so the retic will be checked closely for several weeks.
Bilirubin Test
What is it?
The bilirubin test is how they will monitor baby's bilirubin (bili) and decide how to treat the baby.
When is it done?
Bilirubin should be tested at birth, and frequently thereafter.
Where is it done?
This test is usually done in the hospital or at a laboratory.
Why is it done?
The bilirubin test is done to see how much bilirubin is in the baby's system. Bilirubin can build up with the destruction of red blood cells, and can cause brain damage.
How is it done?
This test can be done by taking blood from the umbilical cord or through a heel stick. Occasionally a device called a bilichek can be used to check the bilirubin by scanning the infant's forehead. Some doctors do not believe the bilichek is accurate enough for babies with ISO and prefer the blood draws. Others will use a mixture of both, alternating heel sticks with the bilichek.
How often is it done?
Bilirubin should be checked immediately after birth and as frequently as every 4 hours afterwards. If the levels aren't too high, your doctor may do every 12 hours until discharge, and then daily for the first week or two. Bilirubin tends to peak around day 4 or 5 with ISO babies. One thing to watch out for, is rebounding jaundice. ISO babies tend to have a decrease in bilirubin when on lights, but rapidly increase when the lights are removed. This can occur up to 3-4 days after removal from lights, so keep checking the bilirubin levels even after treatment has ended. Bilirubin levels will still be checked periodically by the doctor for the first month or so of baby’s life (weekly or biweekly after treatment ends).
What do the results mean?
Below is the common bilirubin graph. First determine your baby's age in hours, then plot your results.
You can also use the tools at http://peditools.org/bili/index.php to plug in your baby's information.
Bilirubin comes as 3 parts: total serum bilirubin, indirect bilirubin (sometimes called unconjugated), and direct bilirubin (conjugated). Healthy term infants may tolerate serum bilirubin levels of 25 mg/dl. Infants are more prone to the toxic effects of bilirubin if they have any of the following: acidosis, prematurity, septicemia, hypoxia, hypoglycemia, asphyxia, hypothermia, hypoproteinemia, exposure to drugs that displace bilirubin from albumin, or hemolysis (ISO). For ISO babies (and all babies with at least one of the risk factors above), use the values listed under the complicated.
TOTAL bilirubin should be used when judging baby. DO NOT subtract the direct (conjugated) from the total (49). This is an old practice and is not recommended by the American Academy of Pediatrics.
Phototherapy should be started anytime there's a positive coombs test and the cord blood is more than 3.5 mg/dL. (5) Some doctors use a cord bilirubin of 4 mg/dL as criteria for an exchange transfusion.
If numbers are high
This is the transfusion graph. First determine your risk. If you are having a sensitized pregnancy, you are either medium or high risk. Then determine your baby's age and plot their numbers. If at birth your bili levels are already over 14, there's a good chance you're headed for an exchange transfusion.
The following are indications for exchange transfusion:
Severe anemia (Hb < 10 g/dL)
Cord bilirubin > 4 mg/dL.
Rate of bilirubin rises more than 0.5 mg/dL despite intensive phototherapy
Severe hyperbilirubinemia[59]
Serum bilirubin-to-albumin ratio exceeding levels that are considered safe (5)
IVIG has been shown to reduce the need for an exchange transfusion.
If levels are high, phototherapy and supportive treatment should begin immediately because jaundice severe enough to lead to kernicterus (permanent brain damage), may develop. The goal of therapy is to prevent the concentration of indirect bilirubin from reaching neurotoxic levels.
If numbers are low
Great! You’re probably good to go but the bilirubin levels will still be checked periodically by the doctor for the first month or so of baby’s life.
Additional Information
Bilirubin tends to peak around days 4-6 with ISO babies. One thing to watch out for, is rebounding jaundice. ISO babies tend to have a decrease in bilirubin when on lights, but rapidly increase when the lights are removed. This can occur up to 3-4 days after removal from lights, so keep checking the bilirubin levels even after treatment has ended.
Don't delay on bilirubin treatment because it can cause irreparable brain damage and Kernicterus. See the sections on Jaundice and Kernicterus in "After Birth Complications". One of the complications of bilirubin is Bronze Baby Syndrome (part 7).
Neutrophil Count
What is it?
The neutrophil count is how they will monitor baby's neutrophils and decide how to treat the baby.
When is it done?
The neutrophil count should be tested at birth, and every 1-2 weeks depending on numbers.
Where is it done?
This test is usually done in the hospital or at a laboratory.
Why is it done?
Up to half of all iso babies develop isoimmune neonatal neutropenia (INN) (38). This test checks to make sure that baby is not neutropenic.
How is it done?
Neutrophil counts are done from a blood sample. Frequently they are part of a CBC, but check with your doctor or lab to make sure.
How often is it done?
It is done every 1-2 weeks depending on numbers. If checking baby for late onset anemia, it would be easy to check the neutrophil count at the same time. Low neutrophil count can persist for up to 28 weeks.
What do the results mean?
Below are two tables for the range of neutrophils in term and preterm infants. (41)
If numbers are high
Your baby is not neutropenic.
If numbers are low
Neutropenia is defined as an absolute neutrophil count (ANC) of less than 1.5 (x109/L)
Additional Information
Neutropenia resolves within 11 weeks, but can persist as long as 28 weeks 39.
Platelet Count aka Thrombocyte count
What is it?
The platelet count is how they will monitor platelets and decide how to treat the baby.
When is it done?
The platelet count should be tested at birth, and every 1-2 weeks depending on numbers.
Where is it done?
This test is usually done in the hospital or at a laboratory.
Why is it done?
Iso babies are at risk of developing isoimmune thrombocytopenia. This risk is higher if baby had to have IUTs.
How is it done?
Platelet counts are done from a blood sample. Frequently they are part of a CBC, but check with your doctor or lab to make sure.
How often is it done?
It is done every 1-2 weeks depending on numbers. If checking baby for late onset anemia, it would be easy to check the platelet count at the same time.
What do the results mean?
Thrombocytopenia is defined as a platelet count of less than 150 x 109/L. This value is the same regardless of age. (45)
If numbers are high
Your baby is not thrombocytopenic.
If numbers are low
Thrombocytopenia is defined as a platelet count of less than 150 x109/L.
Newborn Blood Screening
What is it?
The newborn blood screening is a required test to check for dangerous medical conditions.
When is it done?
This test is done sometime after birth and before discharge.
Where is it done?
This test is usually done in the hospital.
Why is it done?
This test is required by law in the USA.
How is it done?
A heel stick is done and drops are placed on a card to be sent for testing.
How often is it done?
Usually once, BUT if you baby has had transfusions, IUT or post birth, it is advisable to retest at 1 year old.
What do the results mean?
Here’s the interesting part - if you’ve had IUTs or post birth transfusions (before the newborn screen), your baby has donor blood. The newborn screening isn’t just testing your newborn’s blood, but the blood of all the donors for all the transfusions. You can redo the newborn testing at 4 months, but in cases of severe antibodies with multiple post birth transfusions, waiting until 1 year old is good to make sure that all the donor blood is out of baby’s system.