The purpose of this study is to explore a potential exposure risk in the neonatal intensive care unit, namely, the iatrogenic microplastic exposure that critically ill newborns may face when receiving life-saving parenteral nutrition (intravenous nutrition delivered through a plastic infusion system). Therefore, the investigators designed a prospective study. By comparing three groups of newborns-those requiring long-term intravenous nutrition, short-term intravenous nutrition, and no intravenous nutrition-and collecting blood samples with strictly contamination-proof non-plastic instruments, the investigators used high-precision Raman spectroscopy for detection. For the first time, they attempted to systematically and quantitatively analyze the microplastic load in neonatal blood and its relationship with the duration of intravenous nutrition. The aim of this study is to provide novel scientific evidence for evaluating microplastic exposure in the neonatal medical environment, with the ultimate goal of establishing a basis for developing safer clinical practices and medical material standards in the future, thereby better protecting the long-term health of vulnerable newborns.