Causes of leg swelling in pregnancy

It commonly affects both feet or ankles and may become more noticeable later in the day, in hot weather or after prolonged standing. Sudden, marked or one-sided swelling needs a different level of attention.

Pregnancy changes circulation and encourages the body to retain fluid. As the uterus grows, pressure on pelvic veins can slow blood returning from the legs, allowing fluid to collect in tissues around the ankles and feet.

Swelling can also occur with a blood clot, infection or pre-eclampsia. Pre-eclampsia can present with rapidly increasing swelling, particularly when accompanied by severe headache, vision changes, pain below the ribs, nausea or feeling very unwell.

Rest with your legs supported, change position regularly and avoid standing still for long periods. Comfortable shoes, gentle walking and ankle movements can help circulation. Compression stockings may be suitable, but ask your maternity clinician about the correct type and fit.

Note whether the swelling is on both sides, when it began and which symptoms occur with it. This helps the maternity team decide whether blood pressure, urine, circulation or another cause should be checked.

Contact your maternity unit urgently for sudden swelling of the face, hands or legs, especially with severe headache, blurred vision, flashing lights or upper abdominal pain. Get urgent medical help for one leg that becomes swollen, painful, warm or red. Call emergency services for breathlessness, chest pain, coughing blood, collapse or severe difficulty breathing.

Ask whether the pattern fits pregnancy-related fluid retention, whether your blood pressure and urine need checking, and whether compression stockings or changes to activity are appropriate for you.