Observational study of pregnant women with a previous spontaneous abortion before the 10th gestation week with and without antiphospholipid antibodies

Background: A clinical subtype of purely obstetrical antiphospholipid antibody (aPL-Ab) syndrome (APS) requires three or more unexplained consecutive embryonic losses before the 10th week of gestation associated with persistently positive lupus anticoagulant (LAC), and/or anticardiolipin IgG or IgM, and/or anti-beta 2-glycoprotein I (a beta 2GpI) IgG or IgM. Although this diagnostic classification of APS appeared to be the most sensitive, the APS-associated serological criteria are still debated. Patients/methods: We prospectively observed the second pregnancy of 284 women with a previous embryonic loss, both with and without aPL-Ab. Results: aPL-Ab-positive women were more prone to pregnancy loss, embryonic loss, pre-eclampsia, placental abruption and intrauterine fetal growth restriction. Type IIa aPL-Ab positivity (LAC present alone) was associated with the highest risk of recurrent embryonic loss and intrauterine growth restriction. Type I aPL-Ab positivity (combinations of aPL-Ab type positivity) was associated with the strongest risks of late complications, pre-eclampsia and placental abruption. Finally, a beta 2GpI-M positivities were not clinically relevant in these women. Conclusion: Patients with a first unexplained pregnancy loss before the 10th week of gestation who are also positive for aPL-Abs have a higher risk of various complications in their second pregnancy. In this study, measurement of a beta 2GpI-M had a questionable prognostic value.