Pregnancy in CKD stages 3 to 5 : Fetal and maternal outcomes

Background Prognostic criteria to inform women with moderate to severe renal insufficiency who wish to bear children are not well established. Study Design Longitudinal multicenter cohort study. Settings & Participants Nondiabetic white women with pregnancies proceeded beyond the 20th week and estimated glomerular filtration rate (GFR) less than 60 mL/min/1.73 m 2 ( 2 ) before conception. Predictors Baseline GFR and proteinuria (exposure); other clinical characteristics at conception (covariates). Outcomes & Measurements Difference in GFR decreases before conception versus after delivery (mixed linear models); low birth weight ( Results 49 women were studied. Mean serum creatinine and GFR at conception were 2.1 ± 1 (SD) mg/dL (186 ± 88 μmol/L) and 35 ± 12 mL/min/1.73 m 2 (0.58 ± 0.2 mL/s/1.73 m 2 ), respectively. Overall mean GFR after delivery was less than before conception (30 ± 13.8 versus 35 ± 12.2 mL/min/1.73 m 2 [0.50 ± 0.23 versus 0.58 ± 0.20 mL/s/1.73 m 2 ]; P P = 0.661). Independent of potential confounders, the combined presence of baseline GFR less than 40 mL/min/m 2 ( 2 ) and proteinuria with protein greater than 1 g/d, but not either factor alone, predicted faster GFR loss after delivery compared with before conception (1.17 ± 1.23 versus 0.55 ± 0.39 mL/min/mo; difference, 0.62 mL/min/mo; 95% confidence interval [CI], 0.27 to 0.96 mL/min/mo [0.020 ± 0.021 versus 0.0092 ± 0.007 mL/s/mo; difference, 0.10 mL/s/mo; 95% CI, 0.005 to 0.016 mL/s/mo]). The presence of both risk factors, but not either alone, also predicted shorter time to dialysis therapy or GFR halving (N = 20; hazard ratio, 5.2; 95% CI, 1.7 to 15.9) and low birth weight (N = 29; odds ratio, 5.1; 95% CI, 1.03 to 25.6). Limitations Generalizability to other settings; study power. Conclusion In women with renal insufficiency, the presence of both GFR less than 40 mL/min/1.73 m 2 ( 2 ) and proteinuria with protein greater than 1 g/d before conception predicts poor maternal and fetal outcomes.