A Randomized Control Trial (RCT) conducted in two tertiary level Neonatal Intensive Care Unit (NICU). Ethical approval is needed. Informed and written consent will be obtained prior the delivery from the parents of the babies before the inclusion in the study. All inborn Very Low Birth Weight (VLBW) infants (Birthweight less than 1500 g and Gestational Age < 32 weeks) with signs of RDS, spontaneously breathing and only supported by nasal-Continuous Positive Airway Pressure (NCPAP) in NICU, will be randomized within the first 2 hours of life to receive two different Non Invasive Ventilation (NIV) strategies: Nasal Synchronized Intermittent Positive Pressure Ventilation (N-SIPPV) or Bilevel Continuous Positive Airway Pressure (BiPAP).