Neonates are defined as babies up to 28 days after birth. [1] Most extremely preterm babies (less than 28 weeks) require at least one red cell transfusion; [2] this is partly due to the amount of blood removed with blood samples compared to the baby's total blood volume (iatrogenic anemia) [3] and partly due to anemia of prematurity. Most transfusions are given as small volume top-up transfusions to increase the baby's hemoglobin above a certain pre-defined level, or because the baby is unwell due to the anemia. [2] Possible side-effects of anemia in babies can be poor growth, lethargy and episodes of apnea. Exchange blood transfusion is used to treat a rapidly rising bilirubin that does not respond to treatment with phototherapy or intravenous immunoglobulin. [4] This is usually due to hemolytic disease of the newborn, but may also be due to other causes, e.g., G6PD deficiency.
Below are suggested transfusion thresholds for very preterm neonates (less than 32 weeks gestation) by the British Society of Haematology. [2] These are based on systematic reviews of transfusion in very preterm babies. [5] [6]
Age after birth | No respiratory support Hb g/L | On oxygen Hb g/L | Requiring ventilation Hb g/L |
---|---|---|---|
Up to 24 hours | < 100 | < 120 | < 120 |
1 to 7 days | < 100 | <100 | < 120 |
8 to 14 days | < 75 | < 95 | < 100 |
More than 14 days | < 75 | < 85 | < 100 |
There is no evidence for red cell transfusion thresholds in preterm neonates between 32 and 37 weeks gestation, and the British Society of Haematology suggests using the same thresholds as very preterm neonates that require no respiratory support. [2]
A small volume transfusion is usually 10 to 20 ml/kg administered at a rate of 5 ml/kg/hour. [1] [2]
A large volume transfusion is the estimated entire blood volume of the baby (80 ml/kg) and is usually given during cardiac surgery. [1]
A red cell exchange transfusion is usually given to treat severe hyperbilirubinemia or anemia in babies with hemolytic disease of the newborn. It removes neonatal red cells coated with maternal antibody and reduces the level of bilirubin. A ‘double volume exchange’ (160–200 ml/kg) removes around 90% of neonatal red cells and 50% of bilirubin. [1]
The specification of the blood product differs depending on whether it is to be used for a small volume, large volume or exchange transfusion. [1] [7]
There does not appear to be any benefit to giving fresher red blood cells (less than a week from donation) compared to standard red cells (usually two weeks after donation) for small volume transfusions. [8]
The Serious Hazards of Transfusion (SHOT) hemovigilance reporting scheme has shown that there are a disproportionate number of transfusion errors in babies. There are multiple reasons why this occurs. [9] It can be due to confusion between samples from the mother and the baby, birth of more than one baby, babies who don’t yet have a first name, or that no ID information has been attached to the baby (e.g. wristband). [8] [9] [10]
Paedipacks are multiple aliquots made from one adult blood donation. By using paedipacks, the baby is exposed to blood from fewer blood donors. [1]
ABO blood grouping and screening for antibodies in neonates differs from blood grouping in adults and older children. [8] Any antibodies detected are the mother's antibodies rather than the baby's. [8] Therefore, any donor blood given to the baby must be ABO and D compatible with both mother and baby; and antigen-negative for any clinically significant maternal antibodies. [2] [8]
Necrotising enterocolitis may occur after a red cell transfusion in neonates, although there is an association between the two there is no evidence that the transfusion causes the disorder. [2]
Kernicterus is a bilirubin-induced brain dysfunction. The term was coined in 1904 by Christian Georg Schmorl. Bilirubin is a naturally occurring substance in the body of humans and many other animals, but it is neurotoxic when its concentration in the blood is too high, a condition known as hyperbilirubinemia. Hyperbilirubinemia may cause bilirubin to accumulate in the grey matter of the central nervous system, potentially causing irreversible neurological damage. Depending on the level of exposure, the effects range from clinically unnoticeable to severe brain damage and even death.
Rh disease is a type of hemolytic disease of the fetus and newborn (HDFN). HDFN due to anti-D antibodies is the proper and currently used name for this disease as the Rh blood group system actually has more than 50 antigens and not only the D-antigen. The term "Rh Disease" is commonly used to refer to HDFN due to anti-D antibodies, and prior to the discovery of anti-Rho(D) immune globulin, it was the most common type of HDFN. The disease ranges from mild to severe, and occurs in the second or subsequent pregnancies of Rh-D negative women when the biologic father is Rh-D positive.
Hereditary spherocytosis (HS) is a congenital hemolytic disorder wherein a genetic mutation coding for a structural membrane protein phenotype causes the red blood cells to be sphere-shaped (spherocytosis), rather than the normal biconcave disk shape. This abnormal shape interferes with the cells' ability to flex during blood circulation, and also makes them more prone to rupture under osmotic stress, mechanical stress, or both. Cells with the dysfunctional proteins are degraded in the spleen, which leads to a shortage of erythrocytes and results in hemolytic anemia.
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus at or around birth, when the IgG molecules produced by the mother pass through the placenta. Among these antibodies are some which attack antigens on the red blood cells in the fetal circulation, breaking down and destroying the cells. The fetus can develop reticulocytosis and anemia. The intensity of this fetal disease ranges from mild to very severe, and fetal death from heart failure can occur. When the disease is moderate or severe, many erythroblasts are present in the fetal blood, earning these forms of the disease the name erythroblastosis fetalis.
Neonatal jaundice is a yellowish discoloration of the white part of the eyes and skin in a newborn baby due to high bilirubin levels. Other symptoms may include excess sleepiness or poor feeding. Complications may include seizures, cerebral palsy, or kernicterus.
In ABO hemolytic disease of the newborn maternal IgG antibodies with specificity for the ABO blood group system pass through the placenta to the fetal circulation where they can cause hemolysis of fetal red blood cells which can lead to fetal anemia and HDN. In contrast to Rh disease, about half of the cases of ABO HDN occur in a firstborn baby and ABO HDN does not become more severe after further pregnancies.
Hemolytic disease of the newborn (anti-Kell1) is the second most common cause of severe hemolytic disease of the newborn (HDN) after Rh disease. Anti-Kell1 is becoming relatively more important as prevention of Rh disease is also becoming more effective.
Hemolytic disease of the newborn (anti-Rhc) can range from a mild to a severe disease. It is the third most common cause of severe HDN. Rh disease is the most common and hemolytic disease of the newborn (anti-Kell) is the second most common cause of severe HDN. It occurs more commonly in women who are Rh D negative.
An exchange transfusion is a blood transfusion in which the patient's blood or components of it are exchanged with other blood or blood products. The patient's blood is removed and replaced by donated blood or blood components. This exchange transfusion can be performed manually or using a machine (apheresis).
Neonatal alloimmune thrombocytopenia is a disease that affects babies in which the platelet count is decreased because the mother's immune system attacks her fetus' or newborn's platelets. A low platelet count increases the risk of bleeding in the fetus and newborn. If the bleeding occurs in the brain, there may be long-term effects.
Anemia of prematurity (AOP) refers to a form of anemia affecting preterm infants with decreased hematocrit. AOP is a normochromic, normocytic hypoproliferative anemia. The primary mechanism of AOP is a decrease in erythropoietin (EPO), a red blood cell growth factor.
The Ii antigen system is a human blood group system based upon a gene on chromosome 6 and consisting of the I antigen and the i antigen. The I antigen is normally present on the cell membrane of red blood cells in all adults, while the i antigen is present in fetuses and newborns.
Packed red blood cells, also known as packed cells, are red blood cells that have been separated for blood transfusion. The packed cells are typically used in anemia that is either causing symptoms or when the hemoglobin is less than usually 70–80 g/L. In adults, one unit brings up hemoglobin levels by about 10 g/L. Repeated transfusions may be required in people receiving cancer chemotherapy or who have hemoglobin disorders. Cross-matching is typically required before the blood is given. It is given by injection into a vein.
Neonatal isoerythrolysis (NI), also known as hemolytic icterus or hemolytic anemia, is a disease most commonly seen in kittens and foals, but has also been reported in puppies. It occurs when the mother has antibodies against the blood type of the newborn.
Hemolytic disease of the newborn (anti-RhE) is caused by the anti-RhE antibody of the Rh blood group system. The anti-RhE antibody can be naturally occurring, or arise following immune sensitization after a blood transfusion or pregnancy.
Drug-induced autoimmune hemolytic anemia also known as Drug-induced immune hemolytic anemia (DIIHA) is a rare cause of hemolytic anemia. It is difficult to differentiate from other forms of anemia which can lead to delays in diagnosis and treatment. Many different types of antibiotics can cause DIIHA and discontinuing the offending medication is the first line of treatment. DIIHA has is estimated to affect one to two people per million worldwide.
Blueberry muffin baby, also known as extramedullary hematopoiesis, describes a newborn baby with multiple purpura, associated with several non-cancerous and cancerous conditions in which extra blood is produced in the skin. The bumps range from 1-7 mm, do not blanch and have a tendency to occur on the head, neck and trunk. They often fade by three to six weeks after birth, leaving brownish marks. When due to a cancer, the bumps tend to be fewer, firmer and larger.
Pyknocytosis is a hematologic state characterized by the presence of pyknocytes in the blood. Pyknocytes are red blood cells that appear distorted, irregular and small with abnormal projections and would typically be identified by a medical scientist and verified by a pathologist on a peripheral blood smear.
An Intrauterine transfusion (IUT) is a procedure that provides blood to a fetus, most commonly through the umbilical cord. It is used in cases of severe fetal anemia, such as when fetal red blood cells are being destroyed by maternal antibodies, or parvovirus B19 infection, homozygous alpha-thalassemia, or twin-to-twin transfusion syndrome. IUTs are performed by perinatologists at hospitals or specialized centers.
Hemolytic jaundice, also known as prehepatic jaundice, is a type of jaundice arising from hemolysis or excessive destruction of red blood cells, when the byproduct bilirubin is not excreted by the hepatic cells quickly enough. Unless the patient is concurrently affected by hepatic dysfunctions or is experiencing hepatocellular damage, the liver does not contribute to this type of jaundice.