Postpartum pulmonary embolism: warning signs, tests and treatment

The NHS describes a pulmonary embolism as a blood clot blocking a blood vessel in the lungs, often a piece of a clot that has broken off from a leg vein and travelled up. The RCOG explains that in pregnancy and after birth the risk begins with a deep vein thrombosis in the leg, calf or pelvis, which is uncommon (1 to 2 in 1,000 women) but most likely in the days just after birth. It adds that dying from a PE is very rare in women who are pregnant or have just had a baby.

That is why recognising clot symptoms in the legs early matters. The separate guide on postpartum DVT covers leg signs, risk and heparin in more detail.

The NHS lists difficulty breathing that comes on suddenly, chest pain that is worse when you breathe in, and coughing up blood, and says you may also have pain, redness and swelling in a leg. The RCOG lists sudden unexplained difficulty breathing, tightness in the chest or chest pain, coughing up blood, and feeling very unwell or collapsing, and says to seek help immediately.

The NHS says to ask for an urgent GP appointment or NHS 111 for sudden breathing difficulty or coughing up blood, and to call 999 or go to A&E for severe difficulty breathing, pain in the chest or upper back, a very fast heartbeat or if someone has passed out. It says not to drive to A&E but to ask someone to drive you or call an ambulance, and to bring your medicines. Do not wait for symptoms to settle.

The RCOG's list of risk factors for venous thrombosis after the birth includes a very long labour of more than 24 hours, a caesarean section, heavy blood loss or a transfusion, and in addition being over 35, a BMI over 30, smoking, a previous clot, thrombophilia, long immobility and pre-eclampsia. Risk is assessed at booking, about 28 weeks, if your situation changes and after the baby is born, to decide on preventive measures such as staying active, stockings and heparin injections.

The NHS says to tell your midwife, health visitor or GP straight away about pain in the chest or difficulty breathing, and to report any one-sided leg pain, swelling or redness. Most DVTs and PEs in pregnancy and after birth are preventable, according to the RCOG.

The RCOG says tests for a suspected PE may include a chest X-ray (which can also find other causes such as a chest infection), a CT scan of the lungs, a ventilation/perfusion (VQ) scan of the lungs, and an ultrasound scan of both legs if you have DVT symptoms. The chest X-ray uses a tiny dose of radiation not considered harmful for you or your baby. The CT and VQ scans each carry a small risk, which has to be weighed against the risk to you and your baby of an undiagnosed PE; the RCOG says the childhood cancer risk after either is extremely low, slightly higher with a VQ scan, while a CT scan gives a higher dose to the breasts and may slightly increase lifetime breast cancer risk. Your doctor discusses which test is best for you.

The NHS says that in hospital you will probably be given an injection of anticoagulant medicine before you get any test results.

The NHS says anticoagulants stop clots getting bigger and prevent new clots forming. If tests confirm a PE you continue with anticoagulant injections for at least 5 days and take anticoagulant tablets for at least 3 months. The RCOG says that after a venous thrombosis treatment is usually recommended for at least 6 weeks after birth, a minimum of 3 months overall, with a choice between continuing heparin injections or warfarin tablets, and that heparin and warfarin are both safe while breastfeeding. Your team decides the choice and duration, and you should never stop blood thinners without advice.

The NHS says you should make a full recovery if the PE is spotted and treated early. The RCOG says you will usually be seen afterwards by your GP, obstetrician or haematologist to discuss thrombophilia testing, contraception (avoiding oestrogen-containing methods) and plans for future pregnancies, where heparin is usually recommended.

The RCOG advises staying as active as you can, wearing graduated compression stockings if advised, drinking normal amounts of fluids, stopping smoking and losing weight before pregnancy if overweight, and starting heparin if your risk assessment recommends it. The NHS adds general advice such as avoiding long periods sitting still, and that after an assisted birth, moving around as much as you can helps prevent clots. Local postnatal care and thromboprophylaxis policies differ between hospitals and UK nations.