Thrombosis occurs when a blood clot forms in the circulatory system. These blood clots stop blood from flowing properly around the body. Thrombosis can lead to serious consequences including stroke – which can be caused by a blood clot in the brain. 

How many children does it affect? 

Thrombosis is less common in children than in adults however, thrombosis can happen at any age, including in young children. About one in 10,000 children will have a thrombosis and children with other illness such as heart disease or cancer are at a much higher risk of developing it. In fact, around one in 200 children in hospital will have a thrombosis. 

What are the symptoms of thrombosis and how is it diagnosed?

Symptoms and severity of thrombosis depend on where the blood clot is in the body and how big it is. Blood clots in the deep veins of the arms or legs can cause painful swelling. Blood clots in the lungs can cause shortness of breath and chest pain. Blood clots of the brain can cause stroke which can have long-term and devastating effects including physical and intellectual disability or even death. In Australia alone, between 300-500 children will have a stroke each year.

Blood clots are diagnosed in different ways. For example, blood clots in the brain are diagnosed by imaging the brain using Magnetic resonance Imaging (MRI) or Computed tomography (CT), whereas blood clots in the arm or leg are diagnosed using an ultrasound.
 
What is the treatment?

Blood clots are treated with blood thinning medications such as heparin. Children who are at high-risk of thrombosis are sometimes given medications to prevent blood clots forming, these medicines include warfarin and aspirin. 

What research is MCRI conducting in thrombosis?

The Haematology Research team are committed to improving the prevention and treatment of blood clots in children. To do this, our team works very closely with teams at the Royal Children's Hospital, who look after children at highest risk of thrombosis. These include Cardiology and Intensive care teams. Our team has a state-of-the-art laboratory where we investigate how blood clots from children are different to adults. We also ensure that new blood thinning medications and blood tests work as expected before using them in children.

References:
https://www.stoptheclot.org/wp-content/uploads/2014/03/Children-and-Blood-Clots.pdf
https://pubmed.ncbi.nlm.nih.gov/20113900
https://strokefoundation.org.au/About-Stroke/Learn/Childhood-stroke

Author:
Dr Chantal Attard is a Senior Research Officer in the Haematology Research team at MCRI. She is passionate about improving the lives of children who are at risk of thrombosis by improving prevention and treatment strategies.