Abstract Background Achieving full enteral nutrition (FEN) is a critical milestone for very low birth weight (VLBW) and extremely low birth weight (ELBW) infants. However, determinants of FEN timing and its clinical implications remain insufficiently characterized in China. To identify factors associated with time to FEN and evaluate its relationship with short-term outcomes in VLBW and ELBW infants. Methods This multicenter retrospective study included 773 preterm infants admitted between January 2019 and June 2023. Infants were stratified into VLBWI ( n = 659) and ELBWI ( n = 114). Clinical characteristics, feeding progression, biochemical markers, and clinical outcomes were analyzed. Multivariable generalized linear models were used to identify factors independently associated with time to FEN. Results In VLBWI, lower gestational age, lower birth weight, and treatment-requiring patent ductus arteriosus (PDA) were independently associated with delayed FEN ( P < 0.05). Delayed FEN was associated with increased risks of necrotizing enterocolitis, bronchopulmonary dysplasia, late-onset sepsis, and severe retinopathy of prematurity, as well as higher levels of cholestasis-related biomarkers. No statistically significant associations were identified in ELBWI. Although infants with prolonged FEN demonstrated higher discharge anthropometric measurements, these findings should be interpreted cautiously because of differences in hospitalization duration. Conclusions In VLBWI, delayed achievement of full enteral nutrition was associated with developmental immaturity, hemodynamic instability, and increased short-term morbidity. Time to FEN may serve as a clinically meaningful marker of overall physiological instability rather than an isolated causal determinant of adverse outcomes. Prospective multicenter studies with standardized feeding protocols are warranted to further clarify the relationship between feeding progression and neonatal outcomes.
Yu et al. (Wed,) studied this question.