Associations among perinatal factors and age of achievement of full oral feeding in very preterm infants

Background: Progress to full oral feeding from a tube or parenteral feeding is a complex process for very preterm infants born before 32 weeks of gestation. The influence of infant characteristics and medical complications on feeding progression has not been studied thoroughly. The aim of this study was to constitute a regression model to estimate the postmenstrual age (PMA) of full oral feeding and the length of transition time from the initiation to completion of oral feeding. Methods: A chart review was conducted on very preterm infants born between 2005 and 2010 in one medical center in Taiwan. All enrolled infants were able to take all nutrition by mouth before discharge. Results: A total of 117 infants fulfilling the criteria were included. The mean PMAs for the initiation and completion of oral feeding were 33.9 ± 1.7 and 35.1 ± 2.0 weeks, respectively. Infants required 7.5 ± 6.6 days from initiation to full oral feeding. The results of a stepwise regression revealed that the reciprocal of birth weight (beta coefficient = 3.81, p < 0.001), moderate-severe bronchopulmonary dysplasia (beta coefficient = 1.21, p < 0.001), necrotizing enterocolitis (beta coefficient = 0.84, p < 0.005), and patent ductus arteriosus (beta coefficient = 0.69, p < 0.01) were predictors for the PMA of full oral feeding. The regression model incorporating those factors explained 62.5% of the variation in the feeding outcome (p < 0.001). Gender, multiple gestations, mild bronchopulmonary dysplasia, intraventricular hemorrhage, and sepsis had no effect on the feeding outcome. None of the explored factors were significantly correlated with transition time. Conclusion: A regression model incorporating significant predictors to estimate the PMA of full oral feeding in very preterm infants was suggested. It could enhance communication between health professionals and parents about the feeding progress of infants born very prematurely.