Background Autoimmune diseases are related with poorer obstetric results than general population, specially in mothers with antiphospholipid antibodies.
Objectives To evaluate factors involved in the increased risk of miscarriages or pregnancy losses in patients with autoimmune diseases. To work out an score to predict future miscarriages in these patients.
Methods Retrospective analysis of pregnant mothers with autoimmune diseases attended in our unit since September 2006 to December 2013. A specific follow-up protocol included an initial clinical and obstetric history, basic blood test and an immunologic profile review. Clinical symptoms, blood pressure and proteinuria were checked monthly, and ultrasonography in every trimester. Pregnancy result was assessed by the High Obstetric Risk Unit. Univariate (chi2 and t Student) and multivariate analysis (logistic regression) was used to assess risk factors for pregnancy loss. A predictive score was worked out with these risk factors and its diagnostic performance assessed by ROC curves. SPSS 20 was used for the statistical analysis, considering significative values if p<0.05.
Results 215 pregnancies in 184 women were included and classified according to mother's autoimmune disease: 52 (24,2%) Primary Antiphospholipid Syndrome (PAPS), 26 (12,1%) with only Antiphospholipid Antibodies (APA), 27 (12,6%) Systemic Erythematosus Lupus (SLE), 28 (13%) SLE with APA, 44 (20,5%) Undifferentiated Connective Tissue Disease (UCTD) and 38 (17,7%) UCTD with APA. A total of 41 (19,06%) miscarriages were reported, 32 (14,8%) in the first 10 weeks of pregnancy and 9 (4.18%) beyond that 10th week. Risk factors for miscarriages in the univariate analysis were mother's age, lupus anticoagulant, IgG and IgM anticardiolipin antibodies, previous miscarriages and PAPS, while UCTD was a protective factor. In the multivariate model only mother's age (OR 0.9, IC 95% 0.8-0.98), lupus anticoagulant (OR 2.5, IC 95% 1.1-5.4), IgG anticardiolipin (OR 4.0, IC 95% 1.8-9.0) and previous miscarriages (OR 2.8, IC 95% 1.2-6.5) were predictors. A Miscarriage Risk Score ranging between 0 and 11 points was built: (Age/29* 0.9) + (Lupus Anticoagulant 2.5) + IgG Anticardiolipin*4) + (Previous Miscarriages*2.8). A ROC curve with an area under curve (AUC) of 0,737 was obtained, with sensitivity and specificity for each cut-off values shown in the table.
Conclusions Mother's age, lupus anticoagulant, IgG anticardiolipin and previous miscarriages may be risk factors for worse pregnancy outcomes in pregnants with autoimmune diseases. A Miscarriage Risk Score including these risk factors could be useful to prevent new miscarriages or pregnancy losses.
Lockshin MD, Kim M, Laskin CA, et al. Prediction of adverse pregnancy outcome by the presence of lupus anticoagulant, but not anticardiolipin antibody, in patients with antiphospholipid antibodies. Arthritis Rheum. 2012 Jul;64(7):2311-8.
Ruiz-Irastorza G, Khamashta MA. Managing lupus patients during pregnancy. Best Pract Res Clin Rheumatol. 2009;23:575-82
Peart, Erica; Clowse, Megan E.B. Systemic lupus erythematosus and pregnancy outcomes: an update and review of the literature. Curr Opin Rheumatol. 2014 Jan 10.
Disclosure of Interest None declared