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How to diagnose hemophilia

How to diagnose hemophilia

Many people who have or have had family members with hemophilia will ask that their baby boys get tested soon after birth.

About one-third of babies who are diagnosed with hemophilia have no other family members with the disorder. A doctor might check for hemophilia if a newborn is showing certain signs of hemophilia.

Diagnosis includes screening tests and clotting factor tests. Screening tests are blood tests that show if the blood is clotting properly. Clotting factor tests, also called factor assays, are required to diagnose a bleeding disorder. This blood test shows the type of hemophilia and the severity.

Families With a History of Hemophilia

Any family history of bleeding, such as following surgery or injury, or unexplained deaths among brothers, sisters, or other male relatives such as maternal uncles, grandfathers, or cousins should be discussed with a doctor to see if hemophilia was a cause. A doctor often will get a thorough family history to find out if a bleeding disorder exists in the family.

Many people who have or have had family members with hemophilia will ask that their baby boys get tested soon after birth. In the best of cases, testing for hemophilia is planned before the baby’s delivery so that a sample of blood can be drawn from the umbilical cord (which connects the mother and baby before birth) immediately after birth and tested to determine the level of the clotting factors. Umbilical cord blood testing is better at finding low levels of factor VIII (8) than it is at finding low levels of factor IX (9). This is because factor IX (9) levels take more time to develop and are not at a normal level until a baby is at least 6 months of age. Therefore, a mildly low level of factor IX (9) at birth does not necessarily mean that the baby has hemophilia B. A repeat test when the baby is older might be needed in some cases. Learn more about the inheritance pattern for hemophilia.

Families With No Previous History of Hemophilia

About one-third of babies who are diagnosed with hemophilia have no other family members with the disorder. A doctor might check for hemophilia in a newborn if:

  • Bleeding after circumcision of the penis goes on for a long time.
  • Bleeding goes on for a long time after drawing blood and heel sticks (pricking the infant’s heel to draw blood for newborn screening tests).
  • Bleeding in the head (scalp or brain) after a difficult delivery or after using special devices or instruments to help deliver the baby (e.g., vacuum or forceps).
  • Unusual raised bruises or large numbers of bruises. If a child is not diagnosed with hemophilia during the newborn period, the family might notice unusual bruising once the child begins standing or crawling.

Those with severe hemophilia can have serious bleeding problems right away. Thus, they often are diagnosed during the first year of life. People with milder forms of hemophilia might not be diagnosed until later in life.

Screening Tests

Screening tests are blood tests that show if the blood is clotting properly. Types of screening tests:

Complete Blood Count (CBC)

This common test measures the amount of hemoglobin (the red pigment inside red blood cells that carries oxygen), the size and number of red blood cells and numbers of different types of white blood cells and platelets found in blood. The CBC is normal in people with hemophilia. However, if a person with hemophilia has unusually heavy bleeding or bleeds for a long time, the hemoglobin and the red blood cell count can be low.

Activated Partial Thromboplastin Time (APTT) Test

This test measures how long it takes for blood to clot. It measures the clotting ability of factors VIII (8), IX (9), XI (11), and XII (12). If any of these clotting factors are too low, it takes longer than normal for the blood to clot. The results of this test will show a longer clotting time among people with hemophilia A or B.

Prothrombin Time (PT) Test

This test also measures the time it takes for blood to clot. It measures primarily the clotting ability of factors I (1), II (2), V (5), VII (7), and X (10). If any of these factors are too low, it takes longer than normal for the blood to clot. The results of this test will be normal among most people with hemophilia A and B.

Fibrinogen Test

This test also helps doctors assess a patient’s ability to form a blood clot. This test is ordered either along with other blood clotting tests or when a patient has an abnormal PT external icon or APTT test external icon result, or both. Fibrinogen is another name for clotting factor I (1).

Clotting Factor Tests

Clotting factor tests, also called factor assays, are required to diagnose a bleeding disorder. This blood test shows the type of hemophilia and the severity. It is important to know the type and severity in order to create the best treatment plan.

How to diagnose hemophilia

When and how a bleeding disorder is diagnosed depends on what type of bleeding disorder the person has, the severity of their condition, and sometimes their gender. It can also depend on how quickly a medical professional spots the symptoms and refers them to a hematologist.

Hemophilia is usually diagnosed by a hematologist — a specialist in disorders of the blood, bone marrow, and lymphatic system. In some cases, bleeding disorders are diagnosed by emergency room physicians, general practitioners, or gynecologists.

How Is Hemophilia Diagnosed?

Babies with severe hemophilia A may be diagnosed at birth and are often diagnosed within the first month of life. Families with a history of hemophilia may even request prenatal testing to check for a bleeding disorder during pregnancy. Babies are not usually tested for hemophilia B until they are a few months old, since factor 9 requires time to develop. Babies with type 3 (severe) von Willebrand disease (VWD) are usually diagnosed within the first year. For those with mild or moderate bleeding disorders, the condition may not be diagnosed until later in childhood or even adulthood.

Tests and What They Show

Some tests can provide proof of low levels of clotting factor, while others are performed to rule out other conditions.

Medical History and Physical Exam

The doctor will take a thorough history, asking about symptoms over time and family history of bleeding disorders that will help them assess risk factors for hemophilia. The doctor may conduct a physical exam to check for pain and swelling associated with joint bleeds or other symptoms.

Clotting Factor Assay

The main test for diagnosing hemophilia is a clotting factor assay. A clotting factor assay involves taking a blood sample and performing a laboratory test to establish the amount of each clotting factor present in the blood. Based on which clotting factor is deficient and how low the level of the factor is, the hematologist can often diagnose the type of bleeding disorder and its severity.

Clotting Tests

Unlike clotting factor assays, which determine the amount of factor, clotting tests check how well the clotting mechanism works. Several different tests examine the makeup of the blood and how effectively it clots. Clotting tests are performed in the laboratory using a blood sample. Hematologists may order these tests to gain a better understanding of what is causing bleeding problems.

Activated partial thromboplastin time (APTT) and prothrombin time (PT) both test how long it takes for the blood to clot. APTT tests the effectiveness of factors 8, 9, 11, and 12. PT tests factors 1, 2, 5, 7, and 10. APTT tests are usually abnormal for people with hemophilia A or B. PT tests are usually normal for people with hemophilia A or B, but abnormal for people with some other deficiencies.

If von Willebrand disease is suspected, the doctor may order a von Willebrand factor ristocetin cofactor activity test. This test examines how well the von Willebrand factor functions. Factor 8 clotting tests can also influence a VWD diagnosis, since some people with VWD have low levels of factor 8.

Genetic Testing

Women with a family history of hemophilia may choose to be tested to find out if they are carriers of the gene before becoming pregnant. Knowing the odds helps some families feel better prepared. Some women who are carriers for hemophilia have mild hemophilia themselves and may be at risk for excessive bleeding after giving birth. Treating clotting deficiency before and after childbirth can help prevent dangerous hemorrhages (bleeds).

Similarly, women with no family history who give birth to a child with a bleeding disorder may undergo genetic testing to find out whether the condition has a familial basis. Some mothers find out they also have low levels of clotting factor and begin treatment. Finding out that genes for bleeding disorders run in the family can be frightening, but it can also encourage other family members to look for symptoms, get tested, and seek treatment that may prevent life-threatening bleeds.

Other Tests

A complete blood count (CBC) can determine whether clotting problems are being caused by an abnormally low level of platelets, blood cell fragments necessary for proper clotting. If platelets are low, bleeding problems may be caused by a platelet disorder and not a bleeding disorder.

Fibrinogen is another test that may be ordered. Fibrinogen is another name for factor 1, and a fibrinogen test measures the level of this factor.

If other tests for VWD are inconclusive, the doctor may order a test of von Willebrand factor multimers to check the structure of the von Willebrand factor proteins; multimers help identify the type of VWD .

Ruling Out Other Conditions

Several other conditions can produce bleeding and bruising like that seen in bleeding disorders. The process of ruling out similar conditions is referred to as differential diagnosis. To list just a few, conditions that may resemble hemophilia, VWD, or another bleeding disorder include vitamin K deficiency, a platelet disorder such as idiopathic thrombocytopenia purpura (ITP), and cancers such as leukemia or lymphoma.

Gender Differences in Diagnosing Hemophilia

Due to the way hemophilia is inherited, doctors believed for many years that only boys and men had bleeding disorders, and girls and women were always asymptomatic carriers. In recent years, more doctors have recognized that symptoms of bleeding disorders tend to be overlooked in women. Part of the explanation for the failure to diagnose and treat females on par with males is due to the fact that there was a poor understanding of how the disease manifests in women. The first symptom of a bleeding disorder for some girls is menorrhagia, or heavy menstrual bleeding, which is often dismissed. Menorrhagia may cause anemia (low red blood cell count) that leads to weakness and fatigue. Later, women with bleeding disorders may have heavier-than-normal bleeding with surgeries, during pregnancy, or after childbirth. Since some bleeding is expected with all of these events, doctors may not recognize an undiagnosed bleeding disorder.

Although Von Willebrand disease affects men and women equally, women are more likely to be diagnosed than men due to heavier-than-normal bleeding with menstruation, pregnancy, and childbirth. About two-thirds of those treated for VWD at hemophilia treatment centers are female.

Women are often diagnosed with VWD much later than men. The average age of VWD diagnosis for women is 34; for men it is 22. About one-fifth of the time, women are diagnosed with VWD by their gynecologist.

What Is the Prognosis For Hemophilia?

With proper treatment, most people with hemophilia can live a normal life span. Most people with hemophilia die from the same conditions as the general population, such as cancer and heart disease. Life expectancy may be slightly shorter for some people with severe, difficult-to-treat bleeding disorders.

How to diagnose hemophilia

When and how a bleeding disorder is diagnosed depends on what type of bleeding disorder the person has, the severity of their condition, and sometimes their gender. It can also depend on how quickly a medical professional spots the symptoms and refers them to a hematologist.

Hemophilia is usually diagnosed by a hematologist — a specialist in disorders of the blood, bone marrow, and lymphatic system. In some cases, bleeding disorders are diagnosed by emergency room physicians, general practitioners, or gynecologists.

How Is Hemophilia Diagnosed?

Babies with severe hemophilia A may be diagnosed at birth and are often diagnosed within the first month of life. Families with a history of hemophilia may even request prenatal testing to check for a bleeding disorder during pregnancy. Babies are not usually tested for hemophilia B until they are a few months old, since factor 9 requires time to develop. Babies with type 3 (severe) von Willebrand disease (VWD) are usually diagnosed within the first year. For those with mild or moderate bleeding disorders, the condition may not be diagnosed until later in childhood or even adulthood.

Tests and What They Show

Some tests can provide proof of low levels of clotting factor, while others are performed to rule out other conditions.

Medical History and Physical Exam

The doctor will take a thorough history, asking about symptoms over time and family history of bleeding disorders that will help them assess risk factors for hemophilia. The doctor may conduct a physical exam to check for pain and swelling associated with joint bleeds or other symptoms.

Clotting Factor Assay

The main test for diagnosing hemophilia is a clotting factor assay. A clotting factor assay involves taking a blood sample and performing a laboratory test to establish the amount of each clotting factor present in the blood. Based on which clotting factor is deficient and how low the level of the factor is, the hematologist can often diagnose the type of bleeding disorder and its severity.

Clotting Tests

Unlike clotting factor assays, which determine the amount of factor, clotting tests check how well the clotting mechanism works. Several different tests examine the makeup of the blood and how effectively it clots. Clotting tests are performed in the laboratory using a blood sample. Hematologists may order these tests to gain a better understanding of what is causing bleeding problems.

Activated partial thromboplastin time (APTT) and prothrombin time (PT) both test how long it takes for the blood to clot. APTT tests the effectiveness of factors 8, 9, 11, and 12. PT tests factors 1, 2, 5, 7, and 10. APTT tests are usually abnormal for people with hemophilia A or B. PT tests are usually normal for people with hemophilia A or B, but abnormal for people with some other deficiencies.

If von Willebrand disease is suspected, the doctor may order a von Willebrand factor ristocetin cofactor activity test. This test examines how well the von Willebrand factor functions. Factor 8 clotting tests can also influence a VWD diagnosis, since some people with VWD have low levels of factor 8.

Genetic Testing

Women with a family history of hemophilia may choose to be tested to find out if they are carriers of the gene before becoming pregnant. Knowing the odds helps some families feel better prepared. Some women who are carriers for hemophilia have mild hemophilia themselves and may be at risk for excessive bleeding after giving birth. Treating clotting deficiency before and after childbirth can help prevent dangerous hemorrhages (bleeds).

Similarly, women with no family history who give birth to a child with a bleeding disorder may undergo genetic testing to find out whether the condition has a familial basis. Some mothers find out they also have low levels of clotting factor and begin treatment. Finding out that genes for bleeding disorders run in the family can be frightening, but it can also encourage other family members to look for symptoms, get tested, and seek treatment that may prevent life-threatening bleeds.

Other Tests

A complete blood count (CBC) can determine whether clotting problems are being caused by an abnormally low level of platelets, blood cell fragments necessary for proper clotting. If platelets are low, bleeding problems may be caused by a platelet disorder and not a bleeding disorder.

Fibrinogen is another test that may be ordered. Fibrinogen is another name for factor 1, and a fibrinogen test measures the level of this factor.

If other tests for VWD are inconclusive, the doctor may order a test of von Willebrand factor multimers to check the structure of the von Willebrand factor proteins; multimers help identify the type of VWD .

Ruling Out Other Conditions

Several other conditions can produce bleeding and bruising like that seen in bleeding disorders. The process of ruling out similar conditions is referred to as differential diagnosis. To list just a few, conditions that may resemble hemophilia, VWD, or another bleeding disorder include vitamin K deficiency, a platelet disorder such as idiopathic thrombocytopenia purpura (ITP), and cancers such as leukemia or lymphoma.

Gender Differences in Diagnosing Hemophilia

Due to the way hemophilia is inherited, doctors believed for many years that only boys and men had bleeding disorders, and girls and women were always asymptomatic carriers. In recent years, more doctors have recognized that symptoms of bleeding disorders tend to be overlooked in women. Part of the explanation for the failure to diagnose and treat females on par with males is due to the fact that there was a poor understanding of how the disease manifests in women. The first symptom of a bleeding disorder for some girls is menorrhagia, or heavy menstrual bleeding, which is often dismissed. Menorrhagia may cause anemia (low red blood cell count) that leads to weakness and fatigue. Later, women with bleeding disorders may have heavier-than-normal bleeding with surgeries, during pregnancy, or after childbirth. Since some bleeding is expected with all of these events, doctors may not recognize an undiagnosed bleeding disorder.

Although Von Willebrand disease affects men and women equally, women are more likely to be diagnosed than men due to heavier-than-normal bleeding with menstruation, pregnancy, and childbirth. About two-thirds of those treated for VWD at hemophilia treatment centers are female.

Women are often diagnosed with VWD much later than men. The average age of VWD diagnosis for women is 34; for men it is 22. About one-fifth of the time, women are diagnosed with VWD by their gynecologist.

What Is the Prognosis For Hemophilia?

With proper treatment, most people with hemophilia can live a normal life span. Most people with hemophilia die from the same conditions as the general population, such as cancer and heart disease. Life expectancy may be slightly shorter for some people with severe, difficult-to-treat bleeding disorders.

Hemophilia is a bleeding disorder that stems from having little to no blood clotting factors, which are specific proteins needed for blood to clot. The disorder usually is inherited, although it also can be acquired.

Hemophilia diagnosis typically begins by examining a person’s family history and the results of several blood tests.

Family history

A family history of hemophilia is present in about 70% of cases, making it a key factor to consider when diagnosing the disorder. Severe hemophilia often is diagnosed within the first year of life, while milder forms of the disease may go unnoticed until adulthood.

Expectant parents with a family history of the disorder may request their unborn child to be tested. Amniocentesis and chorionic villus sampling are two prenatal screening tests that can be used to identify genetic mutations associated with hemophilia in the unborn fetus.

Amniocentesis consists of using a needle to remove a small amount of amniotic fluid from the womb. The fluid is examined in the lab for the presence of hemophilia-causing genetic mutations. It typically is performed during the second trimester of pregnancy.

Chorionic villus sampling involves threading a thin tube through the vagina and cervix to remove a small tissue sample from the placenta, which is the temporary organ that provides oxygen and nutrients to the developing fetus. The collected sample is examined in a specialized lab to assess the presence of mutations in clotting factor genes. This procedure can be performed after the 11th week of pregnancy.

Blood tests

Blood tests used to diagnose hemophilia can be classified as either screening tests, which are used to determine whether blood clots properly, or clotting factor tests, which are used to identify the specific type and severity of hemophilia.

Screening tests

Complete blood count (CBC)

A CBC is a standard way to measure the size and number of red blood cells, as well as the number of various types of white blood cells, platelets, and hemoglobin, which is the oxygen-carrying protein found inside red blood cells. Although a CBC often is normal for people with hemophilia, hemoglobin levels and red blood cell counts may be low if a person experiences unusually heavy or prolonged bleeds.

Activated partial thromboplastin time (APTT) test

This test measures the clotting abilities of factors VIII, IX, XI, and XII in terms of the number of seconds it takes for a clot to form in a sample of blood. In patients with hemophilia, this process may take longer than normal due to the lack of some of these clotting factors.

Prothrombin time test (PTT)

This test complements the APTT by measuring how long it takes for blood to clot through the actions of factors I, II, V, VII, and X. In most patients with hemophilia A and B results from this test will be normal, as these patients typically lack factor VIII and IX, respectively.

Fibrinogen test

Fibrinogen is another name for clotting factor I. A fibrinogen activity test measures how well fibrinogen is helping a blood clot to form, while a fibrinogen antigen test measures the amount of fibrinogen in the blood.

Clotting factor tests

Also known as factor assays, these tests are used to identify the specific type of hemophilia a patient has, as well as to assess its severity. These points are critical to being able to provide effective and appropriate treatment, making this test necessary to establish a diagnosis.

Hemophilia severity generally is classified as either: mild, when a patient has 5–40% of normal clotting factor activity levels; moderate, when clotting factor activity levels are 1–5% of what would be expected; or severe, when clotting factor activity levels are less than 1% of normal.

Last updated: July 15, 2021

Hemophilia News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

Testing for Hemophilia

How to diagnose hemophiliaThe only way to detect hemophilia is through a blood test to measure the clotting factor level. If hemophilia is known to run in a family, newborn babies should be tested.

You can test for hemophilia A and B when a baby is born. The blood can be drawn from the umbilical cord. However, the factor IX level in a newborn baby is lower than it will be later in life. Repeating the test at 6 to 12 months of age can show the factor IX level a person can expect to have the rest of his life.

Can you tell if a baby has hemophilia before it is born?

Another test is called CVS (chorionic villus sampling). In CVS, the doctor removes a small sample of cells from the placenta. A DNA test is done on the sample. It can show the sex of the baby and check for hemophilia. This test can be done earlier than other tests. It is typically done in the 10 th to 13 th week of pregnancy. It takes about ten days to get the results. With CVS, there is about a 1 in 100 chance of having a miscarriage. If done before 10 weeks of pregnancy, there is a risk of causing birth defects.

Another way of testing for hemophilia is PUBS (percutaneous umbilical blood sampling). PUBS directly tests the blood of the unborn baby. It is done after the 20th week of pregnancy. The doctor takes blood from the umbilical vein which runs from the baby to the placenta. The test results are ready in just a few days. PUBS is usually done after other tests have shown that the baby is a boy. This test does not work for all types and levels of hemophilia.

An ultrasound can be done on the pregnant woman at 12 to 18 weeks. The ultrasound gives a picture of the baby inside the womb. Sometimes you can see the sex of the baby.

At the birth of a baby who may have hemophilia A, it is possible to test for the disorder using blood from the umbilical cord. You should wait to test for hemophilia B if there is a family history of mild hemophilia. In that case, the hemophilia B test may not be accurate until the baby is six months old.

Special Precautions

Some couples with family histories of hemophilia may use the knowledge of the baby’s sex to prepare themselves for the child’s potential health problems. The person delivering the baby should not use forceps or vacuum suction if the baby might have hemophilia. She or he should not try to attach monitors to the baby’s scalp. These things could cause bleeding.