Inclusion Criteria:  Birth weight >1400 <2500 gram and gestational week ≥32-37 weeks Who are feeding only human milk Fully enterally fed babies (50-100ml / kg / day) Whose parents signed the informed consent to participate in the study were included.  Exclusion Criteria:  Infants who cannot feed with human milk Who receive intravenous fluid, total parenteral nutrition or mixed fluid Infants with major congenital, cardiac, respiratory or airway abnormalities and infants who require additional pressure and respiratory support Metabolic imbalances, hypoglycemia or electrolyte imbalance Narcotic analgesic or sedation therapy Whose parents did not sign the informed consent were excluded.