ObjectiveTo study the renal effects (measured by creatininemia) of plasma volume expansion with a medium molecular weight hydroxyethyl starch in the newborn.DesignA prospective, randomized, double-blinded, pilot study.PatientsThe study included 26 neonates weighing 690–4030 g (gestational age, 26–40 wks), without cardiac or renal failure or major hemostasis abnormalities and requiring a peripherally inserted central catheter for parenteral nutrition.SettingPediatric and neonatal intensive care unit of a university-affiliated hospital.InterventionsPlasma volume expansion was performed to facilitate insertion of the central catheter. After parental consent, neonates were randomly allocated to receive intravenous infusions at 10 mL·kg−1of 5% albumin or 6% hydroxyethyl starch 200/0.5. Sample size was calculated to detect an increase in mean creatininemia of >20 &mgr;mol·L−1(with &agr; = 0.05, &bgr; = 0.80).Measurements and Main ResultsNo clinically or statistically significant differences were found between the two groups 6 hrs, 24 hrs, 48 hrs, and 7 days after plasma volume expansion. The study could detect an increase in creatininemia ≥20 &mgr;mol·L−1with a power of 80%.ConclusionsIn 13 healthy neonates, plasma volume expansion with 10 mL·kg−1of 6% hydroxyethyl starch 200/0.5 does not increase creatininemia.