Impact of respiratory support on time to achieve full oral feeding in very low birth weight infants: a retrospective study

Background Very low birth weight infants often require respiratory support, which may delay full oral feeding. The independent roles of invasive versus non-invasive support are unclear. This study used propensity score matching to assess their associations with feeding time. Objective To investigate the impact of different durations of respiratory support on the time to achieve full oral feeding in very low birth weight infants, and to provide evidence for early identification of high-risk infants and optimization of respiratory support management. Methods This retrospective cohort study included 753 VLBWI admitted to a tertiary hospital from 2018 to 2024. Infants were dichotomized into long- and short-FOF groups according to the median time to FOF. Propensity score matching (1:1 nearest-neighbor, caliper = 0.1) balanced baseline confounders, yielding 179 matched pairs. Durations of initial invasive mechanical ventilation, non-invasive positive pressure ventilation, and total positive pressure support were compared. Multivariable conditional logistic regression was applied to the matched data to identify independent risk factors for prolonged FOF. Results After PSM, the long-FOF group exhibited significantly longer NIPPV duration (median: 19 vs. 13 days, P < 0.001) and total support duration (23 vs. 15 days, P < 0.001) compared to the short-FOF group, while initial IMV duration showed no significant difference ( P = 0.224). Multivariable analysis demonstrated that both NIPPV duration (aOR = 1.035, 95% CI: 1.015-1.055) and total support duration (aOR = 1.033, 95% CI: 1.015-1.052) were independent risk factors for delayed FOF. In contrast, the independent association of initial IMV duration was model-dependent and not consistently significant after matching. Conclusion The duration of non-invasive positive pressure respiratory support is significantly associated with delayed achievement of full oral feeding in very low birth weight infants.