American Society of Hematology

Blood Clotting & Pregnancy

If you are pregnant, or you have just had a baby, you are at greater risk of developing a blood clot.

Blood clots in pregnant women tend to form in the deep veins of the legs or in the pelvic area. This condition is known as deep vein thrombosis (DVT). Pulmonary embolism (PE) is a life-threatening event that occurs when a DVT breaks off and travels to the blood vessels of the lungs.

DVT and PE, collectively known as venous thromboembolism, are highly preventable (see prevention tips below). The U.S. Surgeon General has issued a Call to Action on DVT and PE to raise public awareness of these blood conditions and increase research on the causes, prevention, and treatment.

Blood clots are also potentially dangerous to your baby. Blood clots can form inside the placenta, cutting off blood flow and harming your baby.

Am I at Risk?

The risk of developing a blood clot during pregnancy is increased by the following:

  • Previous blood clots
  • A genetic predisposition to blood clots
  • Obesity
  • Prolonged immobility (e.g., bedrest, long distance travel)
  • Multiple births
  • Increased maternal age
  • Other medical illness (e.g., cancer, infection)
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How are Blood Clots in Pregnant Women Treated?

Typically, blood clots are treated with an anticoagulant, a medicine that prevents the blood from clotting. Certain anticoagulants are safe to use during pregnancy.back to top

Are Blood Clots Preventable?

There are a few things that you can do to prevent blood clots during pregnancy:

  • Be aware of risk factors.
  • Know your family history.
  • Make sure your doctor knows about any history of blood clots or blood clotting disorders in your family.
  • Remain active, with your doctor's approval.
  • Be aware of the signs and symptoms of a blood clot. Visit your doctor immediately if you think you have one.

If you are pregnant and have concerns about blood clots, talk with your doctor about your risks and prevention. Depending on your condition, your OB-GYN may refer you to a hematologist, a doctor who specializes in treating blood conditions.

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Antiphospholipid Antibody Syndrome: A Patient's Journey

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Where Can I Find More Information?

If you find that you are interested in learning more about blood diseases and disorders, here are a few other resources that may be of some help:

Results of Clinical Studies Published in Blood

Search Blood, the official journal of ASH, for the results of the latest blood research. While recent articles generally require a subscriber login, patients interested in viewing an access-controlled article in Blood may obtain a copy by e-mailing a request to the Blood Publishing Office.

Patient Groups

A list of Web links to patient groups and other organizations that provide information.

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