Resuscitation management: The high-risk resuscitation team attends delivery of all neonates < 35 wks GA. Radical pulse oximeters (Masimo, Irvine, CA) will be set to maximal sensitivity with 2 seconds averaging. Randomization will be done before delivery by opening a sealed, opaque envelope. The probe will be placed on the pre-ductal hand within the first 30 seconds of life using previously described strategies to optimize time to reliable signal as per NRP 2011 guidelines. A neonatal transducer (Invos Cerebral Oximeter Monitor , Covidien, Mansfield, Massachusetts) will be attached to left fronto-pareital forehead to measure continuous near infrared spectroscopy (NIRS) measurements. Apart from the randomly assigned O2 strategy, resuscitation will follow 2011 NRP guidelines. Treatment failure will be defined as HR< 60 bpm after 90 seconds of resuscitation. In this event, the O2 concentration will be increased to 100% as recommended by current NRP guidelines. Once HR is stabilized, FiO2 will be reduced to meet the goal saturations of the assigned strategy. If pulse oximetry does not register stable values, resuscitation will be continued at the current FiO2 as long as HR > 100 bpm is maintained. If HR remains below 100 bpm, after making ventilation correcting steps, FiO2 can be increased by 10-20% based on clinician's judgement.