Methods and techniques to improve the quality and safety of oral feeding in preterm infants are still a significant challenge in modern neonatology. One of the areas that can help improve feeding is choosing the optimal feeding position for premature babies.

PURPOSE: The aim of the study is to compare the advantages of side-lying positioning on the right (SLP-R) and left side (SLP-L) of infant's body, during bottle-feeding of preterm infants.

METHOD: The study will include eight neonates (n=8) born ≤34 weeks of gestational age. Four bottle-feeding sessions will be tested in each of the newborns: two in the SLP-R and two in the SLP-L. The position for the first study will be randomly assign, then positioning will be change after each feeding session. In one day, only two consecutive feeding sessions will be tested which will be included to the study in order to minimize fatigability as a disrupting factor. The levels of saturation (SpO2) and heart rate (HR) will be measured as the parameters indicative of the newborn's physiological stability. The factors determining the qualitative aspect of feeding include the total time of declines of SpO2 ≤85%, level of the newborn's alertness according to the Neonatal Behavioral Assessment Scale (NBAS), and the occurrence of choking episodes. The proportion of milk consumed (volume of milk eaten relative to the expected volume) and the duration of the feeding and feeding session were also will be record. Maximum time of feeding session will be 40 minutes.

Also the posseting during/after feeding and regurgitations will be record in each tested positions.

Inclusion Criteria:

• circulatory and respiratory stability;
• readiness for oral feeding according to each child's Speech-Language Pathologist assessment;
• prematurely born infants who will be in the process of transfer from enteral nutrition to full oral feeding and will be fed orally at least 4 times within twenty-four hours;
• researcher must be a right handed person (right hand is the dominant hand);
• each infant will be fed with one kind of bottle and nipple;
• parents will give a informed consent to participate their infant in the study.

Exclusion Criteria:

• disorders which could significantly affect the feeding course, such as cleft lip and/or palate, facial paralysis and/or congenital defects of the facial skeleton;
• the presence of detected congenital abnormalities and metabolic diseases;
• newborns after abdomen chirurgical treatment;
• low Apgar score (less than 5 points at the 5th and 10th minute of the measurement);
• administered analgesics, anticonvulsants and sedatives <72 hours from extubation prior the trial;
• parenterally fed infants;
• infants with administered intravenous infusion with glucose;
• parents refusal to participate in the study or when bottle-feeding will not be the parental preference.