Aim: To evaluate whether pregnant women with chronic kidney disease (CKD) adapt poorly to increases in renal blood flow. This can exacerbate renal function and impair perinatal outcome, as there is a major interplay between CKD and preeclampsia (PE). Methods: We analyzed the outcomes of 90 pregnant women with preexisting CKD. The estimated glomerular filtration rate (eGFR) was measured along with the levels of angiogenic factors, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor, which might act in the pathophysiology of PE. Results: In pregnancies with CKD, PE and preterm delivery were increased and the increased blood pressure worsened the perinatal outcomes much more than the increased proteinuria. All pregnancies with severe renal insufficiency were delivered preterm because of impaired renal function. The eGFR was correlated significantly with 24-hour creatinine clearance (r = 0.830). Significant differences in sFlt-1 and placental growth factor levels were found between severe PE without any complications and severe superimposed PE (p < 0.05), and between women with and without declining renal function in superimposed PE (p < 0.01). Conclusion: Pregnancies with CKD have a high risk of obstetrical complications. The eGFR might serve for evaluating renal function during pregnancy. Angiogenic factors might be potential markers for a differential diagnosis between PE and worsening renal function. Copyright (C) 2012 S. Karger AG, Basel