Triple Antiphospholipid (aPL) Antibodies Positivity Is Associated With Pregnancy Complications in aPL Carriers: A Multicenter Study on 62 Pregnancies

Objective: Antiphospholipid antibodies (aPL) are risk factors for thrombosis and adverse pregnancy outcomes (APO). The management of the so called "aPL carriers" (subjects with aPL positivity without the clinical criteria manifestations of APS) is still undefined. This study aims at retrospectively evaluating the outcomes and the factors associated with APO and maternal complications in 62 pregnant aPL carriers. Methods: Medical records of pregnant women regularly attending the Pregnancy Clinic of 3 Rheumatology centers from January 1994 to December 2015 were retrospectively evaluated. Patients with concomitant autoimmune diseases or other causes of pregnancy complications were excluded. Results: An aPL-related event was recorded in 8 out of 62 patients (12.9%) during pregnancy: 2 thrombosis and 6 APO. At univariate analysis, factors associated with pregnancy complications were acquired risk factors (p:0.008), non-criteria aPL manifestations (p:0.024), lupus-like manifestations (p:0.013), and triple positive aPL profile (p:0.001). At multivariate analysis, only the association with a triple aPL profile was confirmed (p:0.01, OR 21.3, CI 95% 1.84-247). Patients with triple aPL positivity had a higher rate of pregnancy complications, despite they were more frequently receiving combined treatment of low dose aspirin (LDA) and low molecular weight heparin (LMWH) at prophylactic dose. Conclusion: This study highlights the importance of risk stratification in pregnant aPL carriers, in terms of both immunologic and non-immunologic features. Combination treatment with LDA and LMWH did not prevent APO in some cases, especially in carriers of triple aPL positivity. Triple positive aPL carriers may deserve additional therapeutic strategies during pregnancy.