Docosahexaenoic acid (DHA) has been shown to be particularly important for fetal and neonatal development. Infants born prematurely are at special risk for DHA insufficiency. The source of DHA after birth for preterm babies who are not fed full enterally, are mostly fat emulsions as the component of total parenteral nutrition solutions which usually do not contain DHA. The aim of this study is to investigate if the fish oil emulsion-administered from the first day of life and during parenteral nutrition-prevents infants from cholestasis and retinopathy of prematurity.