Criteria Inclusion Criteria  Parent agreeing to take part in the study Infant starting oral feeding by the doctor in the neonatal intensive care unit and tolerating it Infant born at 26-36+6 gestational week specified according to the last menstruation date of the mother Infant being at 32-39+6 postmenstrual week Infant having a body weight of 1500 grams and above Infant being fed orally once before and tolerating it Infant having no health problem except for being a preterm  Exclusion Criteria  Infant having a gastrointestinal, neurological or genetic illness (such as necrotizing enterocolitis, intracranial bleeding, hydrocephaly, omophalocele, down's syndrome, gastroschisis) and other illnesses Infant having no obstacle to oral feeding (such as cleft palate, cleft lip, facial muscle paralysis, craniofacial anomaly) Infant being on oxygen support