Impact of systemic autoimmune diseases in maternal, fetal and neonatal outcomes in Spain

Pregnancy in autoimmune disease is increasingly feasible but carries heterogeneous maternal and perinatal risks beyond hypertensive disorders. We aimed to quantify disease-specific risks of maternal, foetal and neonatal outcomes across autoimmune diseases in a nationwide cohort, explicitly distinguishing primary vs secondary APS.

We analysed pregnancy-related hospitalizations in Spain (SNHDD, 2016-2022). Exposures were SLE, primary Sjögren syndrome (SjS), MCTD, SSc, sarcoidosis, Behçet disease and APS (primary/secondary). Outcomes included preeclampsia (PE), preeclampsia with severe features (PESC), composite maternal morbidity (caesarean delivery, postpartum hemorrhage, thrombosis, stroke, ICU admission) and composite foetal/neonatal morbidity-mortality (foetal distress, foetal growth restriction, preterm delivery, abruptio placentae, stillbirth, neonatal death).

In 1 973 249 Spanish pregnancy hospitalizations, 5727 involved autoimmune disease. Risks clustered by disease: SLE (PE OR 1.78; PESC 2.17; composite maternal 1.35; foetal/neonatal 1.16), primary APS (PE 1.50; PESC 1.88; maternal 1.66; foetal/neonatal 1.10), secondary APS (PE 2.61; PESC 3.47; maternal 1.94) and MCTD (PE 4.57; PESC 7.24) showed the strongest signals. SSc increased composite maternal (1.62) and foetal/neonatal (1.69) risk; SjS raised caesarean and selected foetal outcomes; Behçet disease mainly increased maternal thrombosis (9.31); and sarcoidosis showed no independent associations.

Pregnancies affected by autoimmune disease exhibit distinct, disease-specific patterns of hypertensive, maternal and foetal/neonatal risk, with the most consistently elevated risks observed in SLE, APS (especially secondary) and MCTD. These comparative estimates may support risk-stratified, guideline-concordant care and inform counseling, surveillance and delivery planning, with explicit consideration of comorbidity burden.