Antiphospholipid Syndrome (APS) is a condition in which the blood is prone to clotting. Phospholipids are fatty molecules that make up part of a cell membrane. In patients with APS, the body mistakenly recognizes certain phospholipids as foreign invaders and produces antibodies to attack them. The process can cause inflammation and clotting of the blood.
Blood clots can develop in any part of the body. A common site of clotting is the brain, which can lead to a stroke. Researchers estimate as many as one-third of strokes in young patients (under 50) are caused by APS. Clotting in the heart can cause a heart attack. About one-third of patients also have heart valve abnormalities. Other common sites of clots include the leg veins (leading to the development of leg ulcers) and kidneys.
APS and Pregnancy Complications
Women with APS may have difficulties with pregnancy. During pregnancy, women are at higher risk of developing blood clots and preeclampsia. Some women may have trouble getting pregnant, while others may experience repeated miscarriages. Blood clots that develop in the placenta can cause fetal growth problems, fetal distress, preterm birth, or pregnancy loss.
There is no cure for APS, but there is treatment. During pregnancy, physicians may recommend low doses of aspirin and daily injections of the blood thinning drug, heparin. The therapy is started at the beginning of pregnancy and halted just before delivery to reduce the risk of bleeding during childbirth. Soon after birth, the treatment resumes for about six weeks because of an increased risk for clotting in the postpartum period.
In one study, a combination of aspirin and heparin reduced pregnancy loss in women with APS by 54 percent. Heparin can cause bone loss, so women may need to take additional calcium during pregnancy. In addition, women need to be monitored for development of a low platelet count.
Over the long term, many doctors recommend women continue to take a low dose of aspirin to reduce the risk of developing dangerous blood clots. Women also need to avoid estrogen therapy (such as birth control or hormone replacement therapy) because estrogen predisposes patients to clotting.
Many women with APS are unaware they have the condition, but it can be diagnosed with a blood test. Doctors may consider the diagnosis when a woman has repeated, unexplained pregnancy loss.
For general information about Antiphospholipid Syndrome:
American Autoimmune Related Diseases Association, Inc., 22100 Gratiot Ave., E. Detroit, MI 48021, www.aarda.org
American Heart Association, www.americanheart.com