Problem  Anti‐beta₂‐Glicoprotein‐1 antibodies (anti‐β₂GPI‐ab) have been related to recurrent miscarriage (RM) with conflicting results. The aim was to evaluate the role of anti‐β₂‐GPI‐ab as unique biological marker in RM related to antiphospholipid (aPL).

Method of study  A cohort study that included 59 cases, divided in two groups, was designed: group 1 comprised 43 pregnant women with ‘obstetric’ antiphospholipid syndrome (APS) and group 2 included 16 cases with similar complaints but only having repeatedly anti‐β₂‐GPI‐ab. Previous thrombosis and/or inherited thrombophilia were excluded. Lupus anticoagulant, anticardiolipin antibodies (aCA), anti‐β₂‐GPI‐ab, and other autoantibodies were analyzed. Miscarriages, premature births, pre‐eclampsia, live births, placental and systemic thromboses were studied.

Results  No differences in previous obstetric complications were detected (P = 1.00–0.164). After the treatment, differences in number of obstetric complications were not seen (P = 1.00). Live births were similar in two groups (88.4% and 93.7%; P = 1.00). Placental thrombosis was equal in both groups, 93.3% versus 80% (P = 1.00).

Conclusion  These results suggest that anti‐β₂‐GPI‐ab may be considered a biological marker for obstetric APS.