"Effects of Targeting Higher vs Lower Arterial Oxygen Saturations on Death or Disability in Extremely Preterm InfantsA Randomized Clinical Trial"
JAMA May 5
http://jama.jamanetwork.com/article.aspx?articleid=1684963 
"Conclusion and Relevance  In extremely preterm infants, targeting oxygen saturations of 85% to 89% compared with 91% to 95% had no significant effect on the rate of death or disability at 18 months. These results may help determine the optimal target oxygen saturation."