- 1) they were unable to begin oral feeding at 32 weeks PMA due to gastrointestinal, craniofacial, cardiovascular, neuromuscular, and/or genetic defects; 2) had surgical necrotizing enterocolitis; or 3) needed ventilator support, including nasal continuous positive airway pressure (CPAP), beyond 32 weeks PMA. Infants receiving oxygen by cannula were included.