PREDICTORS In our published cohort [George et al.] on creatinemia in ELBW infants in the first 6 weeks of life, raised creatinemia reflected immaturity (e.g. gestational age, weight) and morbidity (Apgar, ventilation, retinopathy of prematurity, intraventricular hemmorrhage), but also treatment modalities (e.g. ibuprofen, steroids, parenteral nutrition). We will link the perinatal covariates and creatinine trends to the dataset of this study to explore to what extent perinatal data predict cardiovascular and renal outcome. Since also treatment modalities are included, this study will provide first data on long term cardiovascular and renal outcome following drug exposure.