Nutritional management at 22–23 weeks gestational age: evidence and knowledge gaps

With advancing medical capabilities, survival of infants born at 22-23 weeks' gestation is increasing. However, specific recommendations for nutrition support for these infants are lacking. This review examines the unique characteristics of infants born at 22-23 weeks' gestation that impact parenteral and enteral nutrition support, highlighting the lack of evidence and knowledge gaps for optimal practices. Current recommendations developed for extremely or very low birth weight infants may be unsuitable for infants born at 22-23 weeks' gestation due to important differences in anatomy, physiology, body composition, and metabolic capabilities. Key challenges include severely limited intraluminal digestion, profound immune and microbiome immaturity, and reduced metabolic tolerance to parenteral nutrition provision based on current recommendations, none of which are addressed by recommendations developed for larger, more mature preterm populations. Until more specific studies for infants 22-23 weeks gestation are conducted, clinicians must carefully tailor nutritional support for this vulnerable population given their functional and maturational limitations. IMPACT: Survival of infants born at 22-23 weeks gestation is increasing, but currently available nutrition support recommendations may be inadequate due to the unique physiological, metabolic, and gastrointestinal characteristics that are not accounted for in current parenteral and enteral nutrition support recommendations. This review synthesizes available evidence and identifies critical knowledge gaps in nutrition support management specific to infants born at 22-23 weeks' gestation. We provide a framework to guide individualized clinical decision-making and establish research priorities and collaborative efforts in infants born at 22-23 weeks' gestation.