When to worry about leg pain and swelling in pregnancy with deep vein thrombosis

Deep vein thrombosis is a clot in a deep vein, often in the leg. Pregnancy can make blood clotting more active and can slow blood flow in the pelvic and leg veins. Concerning features can include swelling that is mainly on one side, calf or thigh pain, warmth, redness, tenderness, or a heavy feeling. Normal pregnancy swelling is more often mild, affects both legs, and builds gradually, but appearance alone cannot confirm the cause.

Contact your maternity team or urgent medical service promptly if one leg becomes newly swollen, painful, warm, or red. Tell them how far along you are, when the change began, whether you have had reduced movement, recent travel, surgery, or a previous clot, and which medicines you take. Do not massage a painful swollen leg or start blood-thinning medicine without clinical instruction. Keep your care team informed if symptoms change while you are waiting.

Call emergency services immediately for sudden shortness of breath, chest pain, coughing blood, fainting, a racing heartbeat, or severe weakness. These symptoms can indicate that a clot has affected the lungs. Urgent assessment is also needed for rapidly increasing one-sided swelling or severe leg pain, even when breathing feels normal. Do not drive yourself if you feel faint or short of breath.

What examination or scan is appropriate during pregnancy? Do I need treatment while results are being arranged? Which symptoms should prompt emergency help? How can I stay mobile safely, and will my birth or postnatal plan need review?