What are blood-clotting disorders in children?

Blood-clotting disorders are a group of conditions in which there is too much clotting.

Blood clotting is a normal process. It stops you from bleeding too much when you have a cut or injury. Blood clots can fix damaged blood vessels. Clots often go away on their own.

But blood clots can also form when they aren’t needed, causing serious problems. They may form when there is no injury or bleeding. They can block veins or arteries. This may interrupt blood flow to part of the body. The clots may prevent blood flow to organs such as the brain, lungs, and heart.

Blood-clotting disorders may be diagnosed in childhood. But they are more often found during the teen and young adult years. These disorders are often genetic, meaning they are inherited and present at birth. But there may be no symptoms for many years.

Some inherited clotting disorders are:

• Factor V Leiden. This inherited disorder increases the risk for deep vein thrombosis (DVT) and pulmonary embolism (PE). A DVT is a clot that develops deep in the body, often in the leg. A PE occurs when a blood clot travels through the blood system to the lungs. This clotting disorder also raises the risk for problems with pregnancy, such as pregnancy loss (miscarriage). It's the most common inherited clotting disorder. It occurs most often in children whose families are from Europe. Many people have this disorder. But most never develop harmful blood clots.

• Prothrombin gene mutation (G20210). This is the second most common type of clotting disorder. It increases the risk of the same type of conditions (DVT, PE, and pregnancy problems, including slowed fetal development and miscarriage). It is also most likely to occur in children with families from Europe. Most people with this disorder don’t develop harmful clots, such as a DVT or PE.

• Protein C deficiency. This condition ranges from mild to severe. Many people with this disorder have no symptoms or harmful clots.

• Protein S deficiency. This condition also ranges from mild to severe. As with protein C deficiency, many people have no symptoms or harmful clots.

• Antithrombin deficiency. This inherited disorder increases the risk for blood clots in the veins. It also increases the risk of developing blood clots during pregnancy or soon after delivery.

What causes blood-clotting disorders in a child?

Clotting disorders in children are often inherited conditions. Some illnesses may increase the risk for blood clots.

Which children are at risk for blood-clotting disorders?

Many children with clotting disorders don’t have blood clots. Some things increase the risk of getting clots as children get older. These include:

• Using birth control pills

• Surgery

• Injuries

• Cancer

• Being confined to bed for a long time

• Pregnancy and the 6 weeks after having a baby (postpartum period)

What are the symptoms of blood-clotting disorders in a child?

Clotting disorders have no symptoms. But if a deep vein thrombosis (DVT) forms, the symptoms are:

• Swelling in an arm or leg

• Soreness or pain in an arm or leg

• Red, pale, or bluish skin color

• Coolness or warmth over an area of an arm or leg

A pulmonary embolism is a blood clot in the lungs. This is an emergency. Call 911. Symptoms include:

• Trouble breathing

• Chest pain

• A fast heartbeat

• Coughing

• A slight fever

• Fainting

How are blood-clotting disorders diagnosed in a child?

Your child’s healthcare provider will take your child’s health history and do a physical exam. The provider will also look at your child’s current symptoms and family history. The provider will likely order some tests.

Blood tests may include:

• Complete blood count (CBC). A complete blood count checks the red blood cells, white blood cells, and blood-clotting cells (platelets).

• Clotting tests. This test checks the level of clotting factors in the child's blood and how long it takes to clot.

• Genetic tests. This test checks for gene defects known to cause clotting disorders.

Imaging tests may include:

• Doppler ultrasound. This test shows the blood flow through the vessels. It can see where a blood clot is located.

• CT angiogram or MRI/MRA. This test may be needed if the provider thinks your child may have a pulmonary embolism or a brain blood clot.

How are blood-clotting disorders treated in a child?

Your child's provider will likely refer you to a hematologist. This is a specialist in blood disorders. Medicines are the main treatment for clotting disorders. They include:

• Blood thinners (anticoagulants). These may be given by IV (intravenously) in your child's vein. Or they may be given as a shot (injection), or given in pill form and taken by mouth.

• Aspirin. This may be used with blood thinners, but only if directed by your child's healthcare provider or a hematologist. Taking aspirin can put a child at risk for Reye syndrome. This is a rare but serious disorder that most often affects the brain and the liver. But for some children, the benefits of aspirin reducing blood clotting outweigh this risk. Always talk with your child's provider.

Your child may need to take a blood thinner for a long time. During high-risk times (such as having surgery), your child may need other medicines to help manage or prevent clots. These medicines will often be started while your child is in the hospital. They will be continued at home, often for several weeks or months.

What are possible complications of blood-clotting disorders in a child?

Serious complications from clotting disorders are not common in children. But problems can occur. Complications include:

• Problems with pregnancy and delivery when the child becomes an adult

• Pulmonary embolism

• Stroke, if a clot blocks blood flow in the brain

• Death

How can I help my child live with blood-clotting disorders?

Work with your child's healthcare provider to help prevent clots. As your child gets older, help them avoid things that further increase the risk of blood clots. These include:

• Being overweight

• Being inactive

• Using a hormonal birth control method  

• Smoking

Since there are risks linked to pregnancy, get counseling before considering pregnancy.

When should I call my child's healthcare provider?

Call your child's healthcare provider if your child has symptoms of deep vein thrombosis, chest pain, shortness of breath, or clots anywhere in the body.

Key points about blood-clotting disorders in children

• Blood-clotting disorders are a group of conditions in which there is too much clotting. These disorders may be diagnosed in childhood. But they are often found during the teen and young adult years.

• Many clotting problems are inherited. Some occur with other conditions.

• Blood clots can cause deep vein thrombosis, a blood clot in the lungs (pulmonary embolism), and other serious problems.

• Blood-thinning medicines may be used to treat clotting problems.

• Healthy lifestyle choices can help prevent blood clots. These include staying at a healthy weight and getting regular exercise.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.