Optimal oxygenation at birth and in the neonatal period

Background: In recent years it has become clear that even a brief exposure to high oxygen concentration at birth and an oxygen saturation (SaO(2)) >93-95% in extremely low birth weight (ELBW) infants is more toxic than previously believed.

Objective: To summarize and review clinical studies published to date either dealing with resuscitation of newborn infants with different oxygen concentrations or the use of high or low SaO(2) in the neonatal period of ELBW infants.

Results: Three systematic reviews of five trials and seven individual studies including up to 2,011 newborn infants have shown that neonatal mortality is reduced by 30-40% if resuscitation is carried out with 21% instead of 100% O(2). Room air resuscitation also leads to faster early recovery and need for shorter duration of resuscitation. Six studies of ELBW infants have shown that retinopathy of prematurity and chronic lung disease are significantly reduced if SaO(2) is kept <93-95% compared with higher saturations. Avoidance of fluctuations in SaO(2) also seems to be important. Two observational studies suggest a significant 2.5- to 3.5-fold increased risk of childhood cancer in infants resuscitated with 100% O(2) for a few minutes.

Conclusions: To date there are sufficient data available to recommend that newborn resuscitation should not be carried out with 100% O(2). In ELBW infants, SaO(2) levels should be kept between 85 and 93% or possibly between 88 and 95%, but should definitely not exceed 95%. Fluctuations should be avoided.