Outcomes and treatment of obstetrical antiphospholipid syndrome in women with low antiphospholipid antibody levels.

Our objective was to determine whether there is a relationship between low antiphospholipid (aPL) antibody levels and the obstetrical complications of antiphospholipid syndrome (APS) and to analyze the impact of conventional APS treatment in patients with low aPL levels. To this end, we retrospectively reviewed the files of all patients referred to our unit (2003-2010) for unexplained pregnancy morbidity, with an aPL test result. We compared patients with APS confirmed by Sapporo criteria (Group 1) with patients with APS-like obstetrical complications with an aPL titer below the intermediate titer (Group 2). Overall, 57 patients were included (25 in Group 1; 32 in Group 2). Obstetrical events were recurrent spontaneous abortion <10th week of gestation (n=9 patients in Group 1; n=13 patients in Group 2), fetal death (n=11 and 16, respectively), preeclampsia (n=5 in Group 1; n=6 in Group 2). The total number of obstetrical events per patient was very similar before APS treatment (3 [1-8] in Group 1; 3 [1-6] in Group 2) and decreased significantly after APS treatment to 0 [0-2] and 0 [0-2], respectively (p<0.05). The incidence of premature births and the characteristics of neonates were similar in the two groups. In this study, treatment of patients with low aPL levels and APS-like obstetrical events was associated with outcomes similar to those found in otherwise normal women with recurrent miscarriage or other adverse events. However, properly designed treatment trials would be required to prove the benefit of such treatments.