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Managing deep vein thrombosis or pulmonary embolism in pregnancy - Blood clots in pregnancy

If you have symptoms of a deep vein thrombosis (DVT), your GP or obstetrician will examine your leg. They may refer you for a special ultrasound scan of your leg to see if they can see a clot.

If they are worried that a DVT seems likely, they may start you on treatment while they waiting for your scan. If the scan shows that you don’t have a DVT, this treatment can be stopped.

Treatment for a DVT

If you develop a DVT during your pregnancy, you'll usually need injections of a drug to stop the blood clot getting bigger so your body can dissolve it. This blood thinning drug is called heparin. It's safe to use during pregnancy and does not affect your baby.

You will be shown how to give yourself these injections at home. If you would prefer not to, your partner or another support person can be shown how to inject you.

Heparin also reduces the risk of a pulmonary embolism. You will usually be told to stay on heparin until your baby is at least 6 weeks old.

Other things you can do to help

Other things you can do that could help manage a DVT in pregnancy are:

  • ask your obstetrician, hospital doctor or midwife about whether you should wear compression stockings - these can be prescribed.
  • stay as active as possible.

Managing pulmonary embolism (PE) in pregnancy

Your obstetrician or hospital doctor will examine you and may order some blood tests.

If they think you have a PE, they will order other tests. These may include:

  • a chest x-ray – to check for other things that could cause breathlessness, such as a chest infection
  • a CT scan of your lungs

You might also have a V/Q (ventilation and perfusion) scan. This checks your lungs for PE. It involves a drip being put into a vein in your arm or hand.

Safety of x-rays, CT and V/Q scans during pregnancy

These x-rays and scans involve a small amount of radiation. The amount of radiation in a chest x-ray is so small that it will not harm you or your baby.

CT scans and V/Q scans carry slightly more radiation. These scans have never been shown to cause any harm to an unborn baby. But there may be a very low risk of your baby developing a childhood cancer after these scans. This risk is much less than 1%. But it is slightly higher with a VQ scan than with a CT scan.

Although the risks are tiny, a CT scan or a V/Q scan will only be done during pregnancy if it's really needed.

If there is a risk of your health being in danger from a PE, the benefits of having these tests far outweigh any small risks. Your doctor will discuss all this with you.

Treatment for a PE

Treatment for a PE is the same as the treatment for a DVT.

You will need to continue the treatment until your baby is at least 6 weeks old.

Page last reviewed: 30 April 2021
Next review due: 30 April 2024

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.