Quick read
Key points
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Pregnancy naturally increases the risk of blood clots (venous thromboembolism), because blood clotting factors increase and blood flow in the legs slows down, especially as the pregnancy progresses. Most clots form in the deep veins of the leg (deep vein thrombosis, or DVT), and the main danger is if part of the clot breaks off and travels to the lungs (a pulmonary embolism), which is a medical emergency.
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Topic-specific prevention and risk reduction will be added during the article-specific evidence audit.
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Mild swelling or aching in one leg that is new or getting worse
01 · Know
What is Blood Clots in Pregnancy?
Pregnancy naturally increases the risk of blood clots (venous thromboembolism), because blood clotting factors increase and blood flow in the legs slows down, especially as the pregnancy progresses. Most clots form in the deep veins of the leg (deep vein thrombosis, or DVT), and the main danger is if part of the clot breaks off and travels to the lungs (a pulmonary embolism), which is a medical emergency.
The risk continues for several weeks after birth as well. Your maternity team will assess your individual risk factors and may recommend preventive measures, especially if you have additional risk factors like reduced mobility, a family history of clots, or a caesarean birth.
02 · Understand
Clinical context
Risk assessment is routine
Maternity units routinely assess clot risk at booking and again after birth, and may recommend compression stockings or blood-thinning injections for people at higher risk.
03 · Act
When to Contact Your Maternity Team (Non-Emergency)
- 1Mild swelling or aching in one leg that is new or getting worse
- 2You have risk factors (such as previous clots, reduced mobility, or a family history) and haven't discussed prevention with your team
04 · Prevent & manage
Practical steps
Know the Signs — This Requires Medical Assessment, Not Home Treatment
Suspected blood clots during pregnancy always need prompt medical assessment. The steps below reduce risk but do not replace seeking care if symptoms appear.
- 1Stay as active as your pregnancy allows.Regular movement, even short walks, helps circulation in the legs.
- 2Avoid sitting or standing still for long periods.On long journeys, move your legs and feet regularly, or take breaks to walk.
- 3Stay well hydrated.Good hydration supports healthy blood flow.
- 4Wear compression stockings if prescribed.These are often recommended for people at higher risk and should be worn as advised.
- 5Follow any prescribed injections precisely.If blood-thinning injections are prescribed, take them exactly as directed by your care team.
Medical information notice
Health education, not individual medical advice
BarnMD Health Library provides general health education for public health literacy. Reading this article does not establish a doctor-patient relationship and this information is not a diagnosis, prescription, or personalised treatment plan. If you have symptoms or concerns about your health, seek appropriate advice from a qualified healthcare professional. If you develop emergency warning signs, seek urgent or emergency medical attention.
BarnMD Bottom Line
Pregnancy-related blood clots are taken seriously by maternity teams, and effective prevention and treatment options exist.
Sudden breathlessness, chest pain, or one-sided leg swelling should never be waited out — seek emergency care straight away.