Parenteral Nutrition in Preterm and Sick Newborns

Parenteral nutrition is the intravenous delivery of nutrients — amino acids, lipids, glucose, electrolytes, vitamins, and trace elements — to infants who cannot meet their nutritional needs by the enteral route. In preterm and critically ill newborns it bridges the gap between birth and the establishment of full enteral feeds, supporting growth and nutrient accretion during a period of physiological vulnerability.

Definition

Parenteral nutrition is the provision of nutrients directly into the bloodstream, bypassing the gastrointestinal tract, used in newborns when enteral intake cannot meet nutritional requirements.

Scope

This topic covers what neonatal parenteral nutrition is, its principal macronutrient and micronutrient components, its role while enteral feeds are being advanced, and recognized complications of prolonged use. It is a reference overview within neonatal nutrition and deliberately excludes dosing, prescribing, and individualized management; international guideline frameworks are cited for orientation only.

Core questions

• When is parenteral nutrition indicated in the newborn?
• What are the macronutrient and micronutrient components of neonatal parenteral nutrition?
• How does parenteral nutrition relate to the advancement of enteral feeds?
• What complications are associated with prolonged parenteral nutrition?

Key concepts

• Intravenous amino acids, lipids, and glucose
• Micronutrients (electrolytes, vitamins, trace elements)
• Central versus peripheral venous access
• Transition from parenteral to enteral nutrition
• Parenteral-nutrition-associated liver disease (cholestasis)
• Catheter-related bloodstream infection

Mechanisms

When the immature or compromised gut cannot absorb adequate nutrients, parenteral nutrition supplies them intravenously to sustain energy balance, protein synthesis, and growth. Amino acids support nitrogen accretion, lipid emulsions provide energy and essential fatty acids, and glucose meets baseline energy needs, alongside electrolytes, vitamins, and trace elements. As the gut matures and tolerates feeds, enteral intake is advanced and parenteral support is correspondingly reduced. Prolonged dependence carries recognized risks, including parenteral-nutrition-associated cholestasis and central-line-associated bloodstream infection.

Clinical relevance

Parenteral nutrition is a routine supportive therapy for extremely preterm and sick newborns who cannot yet feed enterally, and its components and duration influence growth and complication risk. This entry describes those concepts and the existence of consensus guideline frameworks as reference material; it does not provide compositions, dosing, or any individualized prescribing guidance.

Epidemiology

Most extremely preterm infants receive parenteral nutrition in the early postnatal period, and network cohorts of these infants document both their dependence on intravenous nutrition and the burden of associated complications such as cholestasis and bloodstream infection. Duration of parenteral nutrition is a measured outcome in neonatal intensive care.

History

The capacity to nourish newborns intravenously developed alongside neonatal intensive care from the late twentieth century, enabling the survival of infants too immature to feed enterally. Accumulating experience and trial evidence were later consolidated into multi-society consensus guidelines (ESPGHAN/ESPEN/ESPR/CSPEN) that codified the components and organization of pediatric and neonatal parenteral nutrition.

Seminal works

• vangoudoever-2018
• lapillonne-2018
• stoll-2010

Frequently asked questions

Why do many preterm newborns need parenteral nutrition?

Extremely preterm infants are often unable to absorb enough nutrients enterally in the first days or weeks of life, so intravenous nutrition supports their growth and energy needs until the gut can tolerate full feeds.

What are the main risks of prolonged parenteral nutrition?

Recognized complications include parenteral-nutrition-associated liver disease (cholestasis) and central-line-associated bloodstream infection, which is one reason enteral feeds are advanced as soon as they are tolerated.