Why is Deep Vein Thrombosis more common during pregnancy?

Expert:Sarah Little, MD, Obstetrician at Brigham and Women’s Hospital

Deep Vein Thrombosis during pregnancy is a serious medical condition. DVT occurs when a blood clot forms in a vein usually in the pelvis or leg. Several things can increase the risk of Deep Vein Thrombosis, including:

• pregnancy
• oral contraceptive use
• obesity
• being sedentary
• surgery

Are there warning signs of Deep Vein Thrombosis during pregnancy?

Although a Deep Vein Thrombosis (DVT) sometimes causes pain and swelling near the clot site, it often has no symptoms. DVT can be fatal if the blood clot breaks off from the wall of vein. If the clot breaks off and travels to the lungs, it can block blood flow and cause chest pain, shortness of breath, heart failure, and kidney damage. This is known as a pulmonary embolism. 

Treatment for Deep Vein Thrombosis during pregnancy

If you are diagnosed with a DVT, you will be given a blood-thinning medication. This will stop the clot from growing, help it dissolve, and reduce your risk of developing more clots.

Why DVT is more common during pregnancy

The heightened risk of DVT continues for about six to twelve weeks after giving birth. Your risk is also increased if:

• you are over 35
• have a family history of blood clots
• are overweight
• underwent fertility treatments
• are carrying multiples
• smoke

Avoiding DVT

You can reduce the risk of Deep Vein Thrombosis during pregnancy by staying active, drinking enough water, and wearing compression stockings.

Though Deep Vein Thrombosis and pulmonary embolism are rare even during pregnancy, it’s a good idea to be aware of the symptoms just in case. If you’re concerned, discuss DVT with you doctor.