Pregnancy outcomes in advanced kidney disease

Maternal and fetal outcomes of pregnant women with advanced chronic kidney disease (CKD stage 4 and 5) are not well chronicled. Since 1980, we could locate only five published case series' studying this population. This study examines nine pregnant women with severe CKD (defined as estimated GFR < 30 mL/min) and compares their materno-fetal outcomes with a cohort of women with an eGFR 45 - 100 mL/min and pre-pregnancy proteinuria (mild CKD). This is a retrospective, single-center study and statistical analyses include Fisher's exact test, nonparametric Wilcoxon rank sum, and exact logistic regression. Compared to women with mild CKD, women with severe CKD have higher rates of pre-term delivery (89% vs. 41%, p = 0.02) and a higher average eGFR reduction during pregnancy (26.1% vs. 0%, p = 0.04). Both groups had similar rate of caesarean section, pre-eclampsia, and adverse fetal outcomes including perinatal death, oligohydramnios, and intrauterine growth retardation. Compared to published outcomes of pregnant women receiving hemodialysis, our cohort of women with severe CKD and not on dialysis had a higher incidence of pre-eclampsia and premature birth. In conclusion, the incidence of pre-term delivery, small for gestational age, and decline of maternal renal function increased with a reduction in eGFR. Women with severe CKD (eGFR < 30 mL/min) may experience a reduced rate of pre-eclampsia and longer gestation with earlier initiation of dialysis.