Antiphospholipid syndrome (APS) can’t be cured but the effects can be controlled. Treatment with anticoagulant (blood-thinning) drugs can help prevent both blood clots and miscarriages. The most commonly used drugs are aspirin, warfarin and heparin.
If you have aPL but no history of clotting, your doctor will probably recommend low daily dose aspirin (75–100 mg). This isn’t guaranteed to prevent blood clots but is known to make the blood less sticky. If you have other factors which increase your risk of clots, or if you suffer from typical APS symptoms such as migraine or livedo reticularis, your specialist may advise you to take warfarin instead of aspirin.
If you have APS and a history of clotting, you’re likely to be given warfarin to prevent further blood clots. Warfarin is taken by mouth. You’ll have regular blood tests (called an INR, or International Normalised Ratio) to check what effect the drug is having, and if necessary your dose will be adjusted. The INR blood tests can be just a finger-prick test or a sample of blood may be sent off for assessment by a laboratory. The most serious side-effect of warfarin during treatment is bleeding. This means that your dosage will be closely monitored.
Warfarin can interact with a number of drugs and foods (for example grapefruit juice), so it’s important that you’re aware of this and take steps to ensure your other medications or diet won’t affect the results of the blood tests.
If you’ve had a number of miscarriages, but no history of clotting, there are two considerations:
- treatment during pregnancy to prevent another miscarriage
- treatment outside pregnancy to prevent clots.
During pregnancy the usual treatment is low-dose aspirin; however, it’s common for pregnant women with APS to be given daily injections of heparin as well as aspirin, especially if the previous miscarriages happened in mid- to late pregnancy or if there have been other pregnancy complications such as pre-eclampsia.
It’s a good idea to be seen in a special pregnancy clinic where the doctors have experience of APS, as well as by your normal obstetrician. Most APS specialists have access to those clinics and you should ask about this if you’re planning to have a baby.
If you’re on warfarin and you become pregnant you’ll probably be changed over to heparin. This is because warfarin is potentially harmful to the baby.