Obstetric antiphospholipid syndrome (Obs-APS) is one of the most commonly identified causes of recurrent pregnancy loss and its accurate diagnosis is a requirement for optimal treatment. Some patients do not fulfill the revised Sapporo classification criteria, the original APS classification criteria, and are considered to be non-criteria Obs-APS. In these patients with non-criteria, there is controversy about their inclusion within the spectrum of APS and eventually their treatment as having Obs-APS. A subset of patients may also have clinical characteristics of Obs-APS even though lupus anticoagulant (LA), anticardiolipin antibodies, and anti-β2-glycoprotein I (aβ2GPI) antibodies are consistently negative. These patients are recognized as seronegative Obs-APS.

We reviewed evidence of non-criteria Obs-APS and discuss a case of a woman with a diagnosis of active systemic lupus erythematosus (SLE) and non-criteria Obs-APS with four consecutive pregnancy losses. After an accurate diagnosis the patient received prenatal counseling and benefited from the optimal treatment of Obs-APS that led to a successful pregnancy. The applicability of this successful experience about outcomes in women with non-criteria, or seronegative, Obs-APS is also evaluated.