Elevated pre-eclampsia risk in lupus nephritis and antiphospholipid syndrome: a nationwide Spanish registry analysis

Objective Evaluate the association of antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE), focusing on lupus nephritis (LN), with risk of preeclampsia (PE) and PE with severity criteria (PESC). Methods Analysis of pregnant women admitted 2016–2022 in the Spanish Hospital Discharge Database. Factors associated with PE and PESC, including early-onset PE, severe PE, eclampsia, and HELLP syndrome, were evaluated. Results Among 1,973 249 admissions, 1,787 patients had SLE (9.1‰), with prior LN in 13.2%. SLE patients experienced higher PE (5.5% vs 2.1%) and PESC (2.1% vs 0.6%) rates; these rose further in SLE women with LN alone (PE: 16.9%, PESC: 5.2%) or with both LN and APS (PE: 18.2%, PESC: 13.6%) (p< 0.05). Adjusted analyses showed PE and PESC were each associated with SLE (OR = 1.78, 95% CI 1.39–2.28; OR = 2.17, 95% CI 1.47–3.22), LN (OR = 1.94, 95% CI 1.18–3.19; OR = 2.45, 95% CI 1.18–5.09) and APS (OR = 1.53, 95% CI 1.28–1.84; OR = 1.91, 95% CI 1.44–2.54). Within SLE patients, baseline hypertension (OR = 4.27, 95% CI 2.45–7.44), LN (OR = 2.06, 95% CI 1.26–3.37) and APS (OR = 1.85, 95% CI 1.03–3.32) were linked to PE, while LN alone predicted PESC (OR = 2.88, 95% CI 1.41–5.91). Conclusion The risk of PE and PESC that patients with SLE exhibit is further amplified in those with a history of LN or APS. Recognizing SLE, APS and especially LN is crucial for precise risk stratification and tailored management to improve maternal and fetal outcomes.