Very low-birth-weight premature infants (VLBWs) are fed via nasal or oro-gastric tube for a long time because of the physiological inability to coordinate swallowing, sucking, and breathing until at least 34 weeks of gestational age.

Both bolus and continuous feeding modes are widely described in the literature; both modes have specific risks and benefits, and there is no evidence in the literature as to which mode is best in terms of tolerance and adverse effects.

To date, the characteristics of enteral feeding that are associated with better feeding tolerance and fewer adverse effects have not been uniquely documented.

There are currently no data in the literature directly comparing different modes of enteral feeding tube management in the preterm VLBW infant. Therefore, our study aims to evaluate different modes of enteral feeding tube management (extemporaneous vs. permanent introduction/removal and oral vs. nasal introduction route) in order to optimize enteral feeding management of the VLBW infant.

The purpose of the study is to evaluate the tolerance of intermittent gastric tube placement versus permanent gastric tube maintenance in preterm VLBW infants who have achieved full enteral feeding, and to record the incidence of adverse effects associated with the different modes of gastric tube management.

Specifically, during bolus feeding, the following parameters will be evaluated in association with the two different management modes:

1. Presence, extent and characteristics of episodes of gastric stagnation
2. Incidence of cardio-respiratory events (desaturation and/or bradycardia)
3. Signs and symptoms of pain/discomfort related to the tube insertion and removal procedure In addition, the above parameters will be examined during enteral feeding with an orally or nasally introduced tube.

Inclusion Criteria:

• Gestational Age <32 weeks and/or neonatal weight <1500 g
• Achievement of full enteral feeding (150 ml/kg/day of milk)
• Exclusive feeding of human milk (breast and/or bank)
• Informed consent signed by parent or legal guardian

Exclusion Criteria:

• Need for invasive ventilatory support
• Congenital malformations affecting the gastrointestinal tract

The study population will consist of all preterm infants of gestational age <32 weeks and/or neonatal weight <1500 g born at sant'orsola hospital. Based on birth data of preterm infants with these characteristics, it is estimated that within one year, approximately 50 infants will be enrolled