Antiphospholipid syndrome, or APS, is an autoimmune disorder in which the body's immune system reacts against certain normal substances present in blood. A person with APS will have a greater than average tendency to form blood clots.
APS is associated with greater odds of pregnancy loss. An estimated 10% to 25% of women with recurrent miscarriages have APS, and a person with APS will often have no other symptoms of the disorder until she experiences recurrent miscarriages. Some controversy exists over whether APS causes late or early pregnancy losses. Most doctors agree that APS can cause late losses but the evidence is unclear on whether APS causes early losses.
As part of the normal recurrent miscarriage workup, doctors test for specific antibodies called anticardiolipin antibodies or lupus anticoagulant antibodies. Testing positive for these antibodies may indicate APS.
Doctors usually treat the condition by having the woman take low-dose aspirin and injections of a blood thinner called heparin during pregnancy. This course of action reduces the odds of forming blood clots and increases the odds of a successful pregnancy.