Antithrombin is another of the natural anticoagulant chemicals in the blood. There are different types of antithrombin deficiency, both genetic and due to other diseases. The inherited form is rare, affecting about 1 in 2,000 people.
Antithrombin deficiency is a fairly severe type of thrombophilia. The risk of having a blood clot varies between families but can be increased by 25-50 times the normal risk. With this condition, a blood clot can occur not only in the legs or lung but also in the veins of the arms, gut, brain or liver. About 1 in 2 people with antithrombin deficiency develop a blood clot before the age of 30 years. Others, however, may reach elderly age without problems.
With this condition, if you do develop a blood clot, you may be advised to take long-term warfarin medication. However, this must be decided on an individual basis. Also, treatment with antithrombin concentrates can be given when there is a higher risk of having a blood clot - for example, if you are having major surgery.
With pregnancy, anticoagulant treatment with heparin is usually needed. Treatment with antithrombin concentrates can also be used.
Note: children can have antithrombin deficiency; parents need to be aware so that they can detect signs of a blood clot. Although most children don't develop a blood clot, they are at risk of them in situations such as surgery. Some newborn babies develop blood clots too. Anticoagulant treatment or antithrombin concentrate may be needed. Parents who have antithrombin deficiency themselves and are expecting a child, should discuss this with their doctor.