It is well known that treatment with aspirin plus heparin is effective for patients with antiphospholipid syndrome (APS) to prevent pregnancy loss. However, it is unclear if occasional antiphospholipid antibodies (aPL) are a risk factor and whether patients with aPL at one time point but not diagnosed as APS should be treated.
Method of study
We therefore studied whether aspirin alone is effective in patients with occasional aPL who did not meet the criteria for APS. We compared live birth rates between 52 patients with occasional aPL treated with aspirin and 672 unexplained patients with no medication. Patients in both group had a history of two or three pregnancy losses.
In all, 44 of 52 patients (84.6%) with occasional aPL could experience live birth when treated with aspirin alone. 509 of 672 patients (75.7%) with unexplained pregnancy losses could have babies. When miscarriage cases caused by an abnormal embryonic karyotype were excluded, the success rates were 95.7% (44/46) and 81.2% (509/621), respectively. The live birth rate in patients with occasional aPL treated with aspirin was significantly higher than that in unexplained patients with no medication (P = 0.008).
We therefore conclude that aspirin is also useful in patients with occasional aPL but not APS.