Background Pulse oximetry is widely used for monitoring oxygen saturation, but uncertainty remains as to most appropriate target range in preterm babies. Studies have been conducted and various target limits have been put forward. BOOST II trial compared outcomes in infants < 28 weeks after randomisation to SpO₂ targeting of 85–89% vs 91–95%. In interim analysis the high target group had increased 36 week survival compared to the low target group.

Aim To find out how much oxygen saturation monitoring policies vary amongst NICUs in the UK.

Methods A telephone survey of level 3 NICUs, caring for babies of less than 28 weeks gestation in theUK using BAPM directory.

Results All 59 units were contacted and had a 100% response rate.

There was wide variation in target limits. We found that despite the interim analysis for BOOSTII trial showing an increased mortality for babies with oxygen saturations at 85–89% compared with 91–95%, 28(47%) units had lower limits less than 89% and 19(33%) units had upper limits set below 95. We also found that 7 (12%) units had upper limits more than 95% which could increase risk of ROP.

Conclusions There is wide variation of unit policies on oxygen saturation targets in very preterm baby across the country. More research and analysis of long term outcomes from the major trials will help us guide to find the optimum targets.