Nasogastric Tube Feeding were used for feeding to provide nutritional support. Each feeding was administered by a nurse using the infant's mother's breast milk through the tube. The amount of each feeding varied from 20 to 100 ml depending on the age of the infant, with feedings given every 2 to 3 hours, approximately 10 times per day. The duration of each feeding procedure ranged from 10 to 20 minutes. The total daily intake ranged from 200 to 1000 ml. Each tube was kept indwelling for 5 to 7 days. When the tube needed to be replaced, it was removed after the last feeding of a day and a new tube was to be inserted through the other nostril on the following morning to continue the nutritional support.

Both groups were given comprehensive rehabilitation therapy. The main intervention measures included: 1) non-invasive ventilator treatment, generally at least once every night and typically not exceeding continuous daily usage.; 2) attention to feeding and sleeping positions, with a recommended sleeping position of lateral recumbent and the head of the bed raised by 20-30°; 3) swallowing function training, such as tongue muscle stretching training, assisted anterior jaw protrusion training, lemon ice stimulation to the soft palate, pharyngeal wall, etc., generally 5 days per week, twice per day, 5-20 minutes each time; 4) pulmonary ultrashort wave therapy, generally at least 2-3 times a week, and not more than once a day; 5) physical therapy, such as intensive training for gross motor functions including lifting the head, turning over, sitting, crawling, standing, etc., generally 3-5 days per week, 1-2 times per day, 5-20 min each time.

The Functional Oral Intake Scale (FOIS) was used to evaluate function of oral intake. In the FOIS assessment, two professional rehabilitation therapists communicated with the patients, observed and recorded to assess their swallowing function. The assessment scale consists of seven levels, with a higher level indicating progressively better swallowing function (less dysphagia).

In this study, the Penetration-Aspiration Scale (PAS) was recruited, which was a commonly used to evaluate the occurrence of penetration or aspiration during swallowing. It categorizes dysphagia into eight levels, with Level 0 indicating no penetration or aspiration and Level 8 indicating severe aspiration. A higher level indicates more severe dysphagia.

The Chinese version of the Swallowing-Quality of Life questionnaire (SWAL-QOL) was used to assess the quality of life of patients.he Likert scale ranging from 1 to 5 was utilized for scoring, with a total of 44 items, including difficulties in swallowing, dietary restrictions, oral health, social communication, and others. The total score was converted to a standard percentage scale ranging from 0 to 100, with positively correlated with quality of life.

The total amount of nutrients consumed by the patient on the day was recorded, excluding fresh water, units: milliliters