Damage accrual related to pregnancies before and after diagnosis of systemic lupus erythematosus: a cross-sectional and nested case-control analysis from a lupus registry

Objective The objective of this study was to evaluate the chronic damage associated with pregnancies before and after the diagnosis of systemic lupus erythematosus (SLE). Methods Using childbearing-aged female SLE patient data registered at the Okayama and Showa University Hospitals, a nested case-control analysis was performed to investigate the relationship between pregnancy and chronic damage using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). Results Pregnancy occurred in 22 patients before and 13 patients after the diagnosis of SLE in 104 eligible patients. Live births occurred in 82% (33/40) and 50% (9/18) of the pregnancies before and after the diagnosis of SLE, respectively. After matching age and disease duration, 33 case patients with chronic damage (SDI ≥ 1) and 33 control patients without chronic damage (SDI = 0) were selected. Hypertension was more frequent in cases than in controls (48% vs. 24%, p = 0.041). Pregnancies before and after the diagnosis of SLE were comparable between cases and controls (before the diagnosis: nine case patients and eight control patients; after the diagnosis: three case patients and five control patients; p = 1.00). Even after adjusting for hypertension using multivariate analysis, the pregnancies before and after the diagnosis were not significant predictors for chronic damage (odds ratio = 1.48 (95% confidence interval 0.33–6.65)), p = 0.60 of the pregnancy before the diagnosis; odds ratio = 0.78 (95% confidence interval 0.13–4.74), p = 0.78 of the pregnancy after the diagnosis). Conclusion Pregnancies, either before or after the diagnosis of SLE, did not show any differences in chronic damage. Our results help alleviate fears regarding childbearing in female patients with SLE and their families.