Long-term impact of pregnancy on renal function among Egyptian women with lupus nephritis: A case control study

Few studies tackled the long-term effect of pregnancy on lupus nephritis (LNs); thus, the study aimed to explore the long-term impact of pregnancy on renal outcomes in Egyptian patients with LN. Group I patients included females who had their first pregnancy after LN onset with ≥5 years elapsing after delivery; group II patients included females who had never got pregnant for ≥7 years after LN onset. Data were retrospectively collected at baseline (T₀) and the last visit (T_last). The study included 43 patients in group I and 39 patients in group II. The comparisons between the two groups regarding the characteristics at T_last showed no significant difference regarding the serum creatinine, estimated glomerular filtration rate (eGFR), renal component of SLICC/ACR Damage Index (SDI) as well as the rate of renal flares, new-onset chronic kidney disease (CKD), progressed CKD and end-stage renal disease. Multivariate regression analysis revealed that systemic hypertension and renal flares were predictors of new-onset/progressed CKD (p = 0.019, OR [95% CI] = 4 [1.3-13]; and 0.022, 13.8 [1.5-128.8], respectively) while pregnancy was not (p = 0.363). Paired comparisons between T₀ and T_last characteristics within each group revealed significant increment of serum creatinine, renal SDI and CKD prevalence; as well as decrement of eGFR in group I (p = 0.004, <0.001, 0.001 and <0.001, respectively) and group II (p = 0.006, <0.001, 0.004 and 0.002, respectively). In conclusion, pregnancy, per se, does not affect the long-term renal outcome in LN patients; however, it is rather dependent on the existence of baseline renal damage and the development of renal flares.