RESUMEN
OBJECTIVE: Determine the mean post-menstrual age when preterm infants attain independent oral feeding skills and whether gestational age, common neonatal morbidities, gender, race, delivery route, or birth year affects this reflex. METHODS: A retrospective chart review of 2700 preterm infants, born before 37 weeks gestational age admitted to a level III NICU between January 1978 and July 2013, to determine the post-menstrual age when independent oral feedings occur. RESULTS: Mean post-menstrual age at achievement of independent oral feeding was 36 + 4/7 weeks ± 14 days. Gestational age under 29 weeks correlated with delayed post-menstrual age at achievement of independent oral feeding at 37 + 3/7 weeks versus 36 + 1/7 weeks for gestational age 29-33 weeks and 36 + 3/7 weeks for late preterm infants (p < 0.0001). Preterm infants with certain morbidities experienced a delay in independent oral feeding: necrotizing enterocolitis at 38 + 6/7 weeks (p < 0.0001), bronchopulmonary dysplasia at 38 + 1/7 weeks (p < 0.0001), severe intraventricular hemorrhage at 37 + 6/7 weeks (p < 0.001). Preterm infants born before the year 2000 achieved independent oral feeding two days later than preterm infants born since the year 2000 (p < 0.0001). Preterm infants delivered vaginally achieved independent oral feeding three days sooner than infants delivered via c-section (p < 0.0001). Female infants orally fed one day sooner than male preterm infants (p = 0.0008). CONCLUSIONS: Preterm infants achieve independent oral feeding at 36 + 4/7 weeks. Factors negatively influencing when the preterm infant will achieve independent oral feeding include gestational age under 29 weeks and major morbidities, whereas vaginal delivery and ongoing advances in neonatal care may accelerate the transition to independent oral feeding.