First, do no trend: aligning parenteral lipid therapy with physiology and evidence in neonates.

Lipid injectable emulsions (ILE) are essential components of parenteral nutrition in neonatal intensive care units. Over the past two decades, the expanded availability of ILE has led to rapid changes in clinical practice, largely driven by concerns about intestinal failure–associated liver disease. Despite these evolving trends, the evidence supporting one ILE over another remains limited and nuanced. Importantly, no currently available ILE replicates the intrauterine supply of critical long-chain polyunsaturated fatty acids, particularly arachidonic acid and docosahexaenoic acid, both of which decline postnatally regardless of emulsion type. Neonates requiring ILE represent a heterogeneous population of preterm and term infants, with surgical and non-surgical diagnoses, often with differing durations of dependence and metabolic needs. A one-size-fits-all approach to ILE therapy may therefore be inappropriate. Alterations in the delicate balance of essential fatty acids may also carry unintended developmental consequences. Hence, clinicians should align ILE selection with physiologic principles, exposure duration, and patient-specific risk profiles. rather than adoption of emerging trends.