<1750 gr, <33 gw infants will enroll study. exckusion criteria: major congenital anomalies major gis anomalies~The study infants are enrolled within 24 hours of birth and sequently randomized to either intermitten feeding (IF) and bolus feeding (BF). Intermittent feeding is defined as delivering enteral nutrition and generally giving 60 min and 2 hours no feeding. this circle repeats 8 times in 24 hours. Bolus feeding is the amount of nutrition put into the syringe was kept 10 cm above the baby and the fluidity was obtained by gravity through the orogastric tube. The data of the patients such as feeding intolerance (gastric residual volume more than %50 of the previous feeding volume, gastric regurgitation, abdominal distension and/or emesis ), whether there is a week-by-week feeding intolerance were noted, NEC, time to reached birth weight, time to achieved full enteral feeding, every 5 minutes during feeding, saturation, respiratory rate and heart rates will record.
achievement of optimal postnatal growth by adequate enteral nutrition in critically ill preterm infants is a challenge of NICU. signs like abdominal distension, reflux, vomiting, nec is a factors of discontinuing fedding in preterm. this factors plays a role in decisions about which method of gavage feeding is adopted. we compare two different feeding method to achive less fedding tolerence.