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 (Tlast). The study included 43 patients in group I and 39 patients in group II. The comparisons between the two groups regarding the characteristics at Tlast 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 Tlast 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.