Anemia in the Newborn

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 protozoan parasite Toxoplasma gondii. Infection occurs when people unknowingly ingest toxoplasma cysts from cat feces or eat contaminated meat... 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. It can occur in three stages of symptoms, separated by periods of apparent good health. Syphilis... 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.

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. It can occur in three stages of symptoms, separated by periods of apparent good health. Syphilis... read more , and human immunodeficiency virus Human Immunodeficiency Virus (HIV) Infection in Children and Adolescents Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and makes people more vulnerable to other infections and some cancers... 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.