The Impact of Masseter Muscle Thickness on the Feeding Process in Preterm Infants in Ultrasound Assessment

The aim of this study is to assess masseter muscle thickness using ultrasounds during oral feeding process in premature infants with gestational age from 28+0/7 to 32+0/7 weeks, taking into account the qualitative and quantitative aspects of oral feeding. The main question it aims to answer is: Does the thickness of the masseter muscle influence the course of development of the feeding function in premature newborns? The study will assess the influence of masseter muscle thickness on the oral feeding process in premature infants, which has significant cognitive value due to the dynamic development of feeding function in this group of newborns. Transitioning from enteral feeding via a nasogastric tube to full oral feeding is a crucial stage in the development of one of the most fundamental life functions - nutrition. Complete, effective, and safe oral feeding is also a factor in determining a newborn's discharge from the hospital. Research in the area of feeding is an important and ongoing goal for improving neonatal care in neonatal units. Furthermore, this study will provide preliminary data on masseter muscle thickness in premature infants, which may serve as a basis for further research.

Inclusion Criteria: * 28+0/7-32+0/7 weeks of gestational age; * use of one specific type of teat; * passive oxygen therapy is permitted; * written informed consent obtained from parents. Exclusion Criteria: * newborns with defects that may significantly affect the development of feeding function such as: cleft lip and/or palate, facial paralysis, and other craniofacial defects; * newborns with a shortened anterior lingual frenulum according to the E. Coryllos classification - meeting the criteria for frenotomy according to the Hazelbaker/Amir scale; * detected genetic defects, metabolic diseases, or suspected cases of their presence; * newborns requiring intubation up to 10 days of life; * low Apgar score (less than 5 points at 5 and 10 minutes of life); * newborns with visible neurological disorders (e.g. with symptoms of hypertonia, impaired reflex reactions in the orofacial area) and/or significant abnormalities in central nervous system (CNS) imaging studies (e.g. III-IV degree intraventricular hemorrhages, CNS defects, hydrocephalus); * newborns of mothers with anhydramnios; * lack of consent to conduct at least two bottle-feeding sessions; * a child fed with a different type of teat than the one used in the study.