Antiphospholipid syndrome (APS) is the name given to a disease which involves the immune system. Normally antibodies are good and they help fight germs or viral infections from outside, however, occasionally the immune system makes the wrong kind - a type that acts against the body itself. These unusual auto-antibodies in APS are detected by a blood test and when they are present make a person more likely to get specific problems.

APS makes some people feel tired or can lead to aching joints but others have no symptoms at all. You can't catch it or give it to someone else and it isn't a terminal disease or anything like that. Many people go throughout life without even knowing their body makes these antibodies. Its just that there's more chance of certain problems. Sometimes APS is associated with a disease called systemic lupus erythematosis (SLE). Your doctor will have tested for this.

It is only recently that these antibodies were discovered and their significance understood, so the information available is somewhat limited, but more research is being carried out on this all the time. We still don't know exactly how the antibodies bring about the effects described below, although we have some good ideas.

What Problems Can it Cause?

The manifestations of APS are very variable and most people will not have more than one of these problems. It is associated with:

Recurring miscarriage in early pregnancy
Loss of a baby after the first trimester (13 weeks)
Pre-eclampsia in pregnancy
Unexpectedly small babies
Thrombosis in a vein or artery

Part of the definition of APS is that one of these must have occurred along with a positive antibody test.

Can These be Prevented?

This is a question that much research is trying to answer, and we know that some treatments can significantly reduce the chances of these things happening.

Pregnancy
One of the most common and distressing problems with APS is that of recurrent miscarriage. A promising treatment which helps prevent this is the use of low dose aspirin in early pregnancy. This is sometimes combined with another drug called heparin, which is given by injection.

Knowing that someone has APS means that the pregnancy can be monitored much more closely than usual, for example with ultrasound scans to watch for poor growth. Indeed, it may be that aspirin or heparin can help prevent these problems too.

Thrombosis
A thrombosis is a blood clot which forms when it shouldn't do, such as in a deep vein of the leg (DVT) or in an artery. Clots from the leg can dislodge and move to more dangerous places such as the lung (pulmonary embolism).

APS can make someone more likely to get thrombosis, but there are times when this is particularly important and thrombosis is already a risk, for example after major surgery, during prolonged illness or bed rest, during pregnancy and for a short time after delivery. During these times, extra clot prevention may be needed. This might mean some tight medical stockings or heparin treatment. In more severe cases of thrombosis, it may mean long-term treatment with tablets to thin the blood. Women with APS shouldn't take the combined (oestrogen-containing) contraceptive pill and a doctor can suggest safer alternatives.

How Common is APS?

The auto-antibodies are found in about 2% of women. Not all of these will have had one of the problems above, so they do not necessarily have the disease. The levels of antibody can go up and down, and even disappear, so to definitely say someone has APS, the blood tests need to repeated at least 8 weeks from the first and still be positive. The decision on treatment at a particular time (such as pregnancy) depends upon the levels and what previous medical problems there were.

APS may run in families, although not all members are necessarily affected. It isn't exactly clear to what extent this happens, but it is certainly suggestive, for example, if several people have had a series of miscarriages or thromboses.

What Can I Do?

When you get pregnant it is important to be referred to your Obstetrician as early as possible to decide on the need for treatment with aspirin or heparin. If you have had a thrombosis, you will have received specific advice on treatment, but probably everyone should be encouraged to address other risk factors for thrombosis. This includes stopping smoking, not using the combined contraceptive pill, treating high blood pressure and cholesterol levels.