Anemia can occur when red blood cells are broken down too rapidly, too much blood is lost, or the bone marrow does not produce enough red blood cells.
If red blood cells are broken down too rapidly, anemia may develop and levels of bilirubin (a yellow pigment produced during the normal breakdown of red blood cells) increase, and the newborn’s skin and the whites of the eyes can appear yellow (a condition called jaundice).
If a large amount of blood is lost very rapidly, the newborn may become seriously ill and develop shock, appear pale, have a rapid heart rate, and have low blood pressure along with rapid, shallow breathing.
If there is less severe blood loss, or the blood is lost gradually, the newborn may appear normal but pale.
Treatment may involve fluids given by vein (intravenously) followed by a blood transfusion or an exchange transfusion.
Red blood cells contain hemoglobin, a protein that gives blood its red color and enables it to carry oxygen from the lungs and deliver it to all body tissues. Oxygen is used by cells to help produce from food the energy that the body needs, leaving carbon dioxide as a waste product. Red blood cells carry carbon dioxide away from the tissues and back to the lungs. When the number of red blood cells is too low, blood carries less oxygen, and fatigue and weakness develop (see also Overview of Anemia Overview of Anemia Anemia is a condition in which the number of red blood cells is low. Red blood cells contain hemoglobin, a protein that enables them to carry oxygen from the lungs and deliver it to all parts... read more in adults.)
Bone marrow contains specialized cells that produce blood cells. Normally, the bone marrow produces very few new red blood cells between birth and 3 or 4 weeks of age, causing a slow drop in the red blood cell count (called physiologic anemia) over the first 2 to 3 months of life.
Very premature newborns Preterm (Premature) Newborns A preterm newborn is a baby delivered before 37 weeks of gestation. Depending on when they are born, preterm newborns have underdeveloped organs, which may not be ready to function outside of... read more have a greater drop in red blood cell count. This condition is called anemia of prematurity. Anemia of prematurity most commonly affects infants whose gestational age Gestational age Problems in newborns may develop Before birth while the fetus is growing During labor and delivery After birth About 9% of newborns need special care after birth due to prematurity, problems... read more (length of time spent in the uterus after the egg is fertilized) is less than 32 weeks and infants who have spent many days in the hospital.
More severe anemia can occur when
Red blood cells are broken down too rapidly (a process called hemolysis).
A lot of blood is taken from premature newborns for blood tests.
Too much blood is lost during labor or delivery.
The bone marrow does not produce enough new red blood cells.
More than one of these processes can occur at the same time.
Rapid breakdown of red blood cells (hemolysis)
Severe red blood cell breakdown results in anemia and high levels of bilirubin in the blood (hyperbilirubinemia Jaundice in the Newborn Jaundice is a yellow color to the skin and/or eyes caused by an increase in bilirubin in the bloodstream. Bilirubin is a yellow substance formed when hemoglobin (the part of red blood cells... read more ).
Hemolytic disease of the newborn Hemolytic Disease of the Newborn Hemolytic disease of the newborn is a condition in which red blood cells are broken down or destroyed by the mother's antibodies. Hemolysis is the breakdown of red blood cells. This disorder... read more is a condition that may cause the newborn’s red blood cells to be destroyed rapidly by antibodies from the mother's blood.
The red blood cells may also be rapidly destroyed if the newborn has a hereditary abnormality of the red blood cells. An example is hereditary spherocytosis, in which the red blood cells look like small spheres when viewed under a microscope.
Another example occurs in infants who lack a red blood cell enzyme called glucose-6-phosphate dehydrogenase (G6PD deficiency Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited genetic disorder that can result in destruction of red blood cells (hemolysis) after an acute illness or use of certain drugs... read more ). In these infants, exposure of the mother and fetus to certain drugs used during pregnancy (such as aniline dyes, sulfa drugs, and many others) may result in rapid breakdown of red blood cells.
Hemolysis may also occur with hemoglobinopathies. Hemoglobinopathies are genetic disorders that affect the structure or production of hemoglobin. Hemoglobin is a protein inside red blood cells that enables the cells to carry oxygen from the lungs and deliver it to all parts of the body. Thalassemia Thalassemias Thalassemias are a group of inherited disorders resulting from an imbalance in the production of one of the four chains of amino acids that make up hemoglobin (the oxygen-carrying protein found... read more is an example of a hemoglobinopathy that can rarely cause problems in newborns.
Infections acquired before birth, such as toxoplasmosis Toxoplasmosis Toxoplasmosis is infection caused by the single-celled protozoan parasite Toxoplasma gondii. Infection occurs when people unknowingly ingest toxoplasma cysts from cat feces or eat contaminated... read more , rubella Rubella Rubella is a contagious viral infection that typically causes mild symptoms, such as joint pain and a rash, but can cause severe birth defects if the mother becomes infected with rubella during... read more , cytomegalovirus infection Cytomegalovirus (CMV) Infection Cytomegalovirus infection is a common herpesvirus infection with a wide range of symptoms: from no symptoms to fever and fatigue (resembling infectious mononucleosis) to severe symptoms involving... read more , herpes simplex virus infection Herpes Simplex Virus (HSV) Infections Herpes simplex virus infection causes recurring episodes of small, painful, fluid-filled blisters on the skin, mouth, lips (cold sores), eyes, or genitals. This very contagious viral infection... read more , or syphilis Syphilis Syphilis is a sexually transmitted infection caused by the bacteria Treponema pallidum. Syphilis can occur in three stages of symptoms, separated by periods of apparent good health. It... read more , may also rapidly destroy red blood cells, as can bacterial infections of the newborn acquired during or after birth.
Blood loss is another cause of anemia. Blood loss in a newborn can occur in many ways. For example, blood is lost if there is a large movement of the fetus's blood across the placenta Development of the Fetus and Placenta A baby goes through several stages of development, beginning as a fertilized egg. The egg develops into a blastocyst, an embryo, then a fetus. During each normal menstrual cycle, one egg (ovum)... read more (the organ that connects the fetus to the uterus and provides nourishment to the fetus) and into the mother's blood circulation (called fetal-maternal transfusion). Blood can also be lost if too much blood gets trapped in the placenta at delivery, which can happen when the newborn is held above the mother’s abdomen for too long before the umbilical cord is clamped.
Twin-to-twin transfusions, in which blood flows from one fetus to the other, can cause anemia in one twin and too much blood (polycythemia Polycythemia in the Newborn Polycythemia is an abnormally high concentration of red blood cells. This disorder may result from postmaturity, diabetes in the mother, twin-to-twin transfusions, in which blood flows from... read more ) in the other twin.
The placenta may separate from the uterus before delivery (placental abruption Placental Abruption Placental abruption is the premature detachment of the placenta from the wall of the uterus, usually after 20 weeks of pregnancy. Women may have abdominal pain and tenderness and vaginal bleeding... read more ), or the placenta may be attached in the wrong place (placenta previa Placenta Previa Placenta previa is attachment (implantation) of the placenta over the opening of the cervix, in the lower rather than the upper part of the uterus. Women may have painless, sometimes profuse... read more ), leading to loss of blood in the fetus.
Blood loss may occur when certain invasive procedures are done to the fetus to detect gene and chromosome abnormalities. Invasive procedures are those that require insertion of an instrument into the mother's body. These procedures include amniocentesis Amniocentesis Prenatal diagnostic testing involves testing the fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including certain hereditary or spontaneous genetic... read more , chorionic villus sampling Chorionic Villus Sampling Prenatal diagnostic testing involves testing the fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including certain hereditary or spontaneous genetic... read more , and umbilical blood sampling Percutaneous Umbilical Blood Sampling Prenatal diagnostic testing involves testing the fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including certain hereditary or spontaneous genetic... read more .
Sometimes blood loss occurs when the newborn is injured during delivery. For example, rupture of the liver or spleen during delivery may cause internal bleeding. Rarely, bleeding can occur under the newborn's scalp when a vacuum extractor or forceps Operative Vaginal Delivery Operative vaginal delivery is delivery using a vacuum extractor or forceps. A vacuum extractor consists of a small cup made of a rubberlike material that is connected to a vacuum. It is inserted... read more is used during delivery.
Blood loss can also occur in newborns who have a deficiency of vitamin K Vitamin K Deficiency Vitamin K deficiency is most common in infants, especially those who are breastfed. The deficiency can cause bleeding; therefore, all newborns should be given a vitamin K injection. Bleeding... read more . Vitamin K is a substance that helps the body form blood clots and helps control bleeding. Vitamin K deficiency can cause hemorrhagic disease of the newborn, which is characterized by a tendency to bleed. Newborns normally have low levels of vitamin K at birth. To prevent bleeding, newborns are routinely given an injection of vitamin K at birth.
Internal bleeding that leads to anemia can occur in babies who are born with a severe, inherited bleeding disorder such as hemophilia Hemophilia Hemophilia is a hereditary bleeding disorder caused by a deficiency in one of two blood clotting factors: factor VIII or factor IX. Several different gene abnormalities can cause the disorder... read more , especially with a difficult delivery.
Frequently drawing a sick newborn's blood may also contribute to anemia.
Decreased red blood cell production
Before birth, the fetus's bone marrow may fail to produce enough new red blood cells. This rare defect may result in severe anemia. Examples of this lack of production include rare genetic disorders such as Fanconi syndrome Fanconi Syndrome Fanconi syndrome is a rare disorder of kidney tubule function that results in excess amounts of glucose, bicarbonate, phosphates (phosphorus salts), uric acid, potassium, and certain amino acids... read more and Diamond-Blackfan anemia.
After birth, some infections (such as cytomegalovirus infection Cytomegalovirus (CMV) Infection Cytomegalovirus infection is a common herpesvirus infection with a wide range of symptoms: from no symptoms to fever and fatigue (resembling infectious mononucleosis) to severe symptoms involving... read more , syphilis Syphilis Syphilis is a sexually transmitted infection caused by the bacteria Treponema pallidum. Syphilis can occur in three stages of symptoms, separated by periods of apparent good health. It... read more , and human immunodeficiency virus Human Immunodeficiency Virus (HIV) Infection in Children Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and causes acquired immunodeficiency syndrome (AIDS). Human immunodeficiency... read more [HIV]) may also prevent the bone marrow from producing enough red blood cells. Rarely, newborns may also be lacking certain nutrients, such as iron Iron Deficiency Iron deficiency is a common cause of anemia, a condition in which the number of red blood cells is low. Iron deficiency usually results from loss of blood in adults (including bleeding from... read more , folate Folate Deficiency Folate deficiency is common. Because the body stores only a small amount of folate, a diet lacking in folate leads to a deficiency within a few months. Not eating enough raw leafy vegetables... read more (folic acid), and vitamin E Vitamin E Deficiency Vitamin E deficiency caused by a diet low in vitamin E is common in countries with high rates of food insecurity. In countries with low rates of food insecurity, the cause is usually an absorption... read more , which may cause anemia because the bone marrow is then unable to produce red blood cells.
Symptoms of Anemia in the Newborn
Most infants with mild or moderate anemia have no symptoms. Moderate anemia may result in sluggishness (lethargy) or poor feeding.
Complications of anemia in newborns
Newborns who have suddenly lost a large amount of blood during labor or delivery may be in shock Shock Shock is a life-threatening condition in which blood flow to the organs is low, decreasing delivery of oxygen and thus causing organ damage and sometimes death. Blood pressure is usually low... read more and appear pale and have a rapid heart rate and low blood pressure, along with rapid, shallow breathing.
When the anemia is a result of rapid breakdown of red blood cells, there is also an increased production of bilirubin, and the newborn’s skin and whites of the eyes may appear yellow (jaundice Jaundice in the Newborn Jaundice is a yellow color to the skin and/or eyes caused by an increase in bilirubin in the bloodstream. Bilirubin is a yellow substance formed when hemoglobin (the part of red blood cells... read more ).
Diagnosis of Anemia in the Newborn
Before birth, prenatal ultrasound
After birth, symptoms and blood tests
Before birth, doctors may do a prenatal ultrasound Ultrasonography Prenatal diagnostic testing involves testing the fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including certain hereditary or spontaneous genetic... read more and may sometimes see signs of anemia in the fetus.
After birth, the diagnosis of anemia is based on symptoms and is confirmed with tests done on a sample of the newborn's blood. Additionally, in some states of the United States, newborns are screened for some of the causes of anemia, such as G6PD deficiency.
Treatment of Anemia in the Newborn
For anemia caused by rapid blood loss, fluids by vein and a blood transfusion
For anemia caused by hemolytic disease, treatment varies
Sometimes iron supplements
Most healthy premature infants have mild anemia and do not require any treatment.
Newborns who have rapidly lost large amounts of blood, often during labor and delivery, are treated with fluids given by vein (intravenously) followed by a blood transfusion Overview of Blood Transfusion A blood transfusion is the transfer of blood or a blood component from one healthy person (a donor) to a sick person (a recipient). Transfusions are given to increase the blood's ability to... read more .
Very severe anemia caused by hemolytic disease may also require a blood transfusion, but the anemia is more often treated with an exchange transfusion Exchange transfusion Jaundice is a yellow color to the skin and/or eyes caused by an increase in bilirubin in the bloodstream. Bilirubin is a yellow substance formed when hemoglobin (the part of red blood cells... read more , which both lowers the bilirubin level and increases the red blood cell count. In an exchange transfusion, a small amount of the newborn’s blood is gradually removed and replaced with equal volumes of fresh donor blood.
Some infants are given liquid iron supplements to help them increase their red blood cell count faster.
Newborns who have jaundice may be treated with phototherapy or "bili lights" Phototherapy or "bili lights" Jaundice is a yellow color to the skin and/or eyes caused by an increase in bilirubin in the bloodstream. Bilirubin is a yellow substance formed when hemoglobin (the part of red blood cells... read more , which help lower the bilirubin level.