The objective of this study is to test the null hypothesis that in preterm infants with gestational age of 28 to 36 weeks who are stable on CPAP pressure of 5 cmH2O and with oxygen concentrations (FiO2) <0.30, keeping these infants on CPAP or changing them to NC flow of 1-2 L/min will not make any difference in length of hospitalization, length of respiratory support and incidence of complications.