Introduction: Most infants born with Pierre Robin Sequence (PRS) will have a degree of obstructive sleep apnoea which improves with jaw growth.  Serial oximetries can demonstrate improvement over time.  The typical trajectory for sleep oximetry is not well described.

Aims and Objectives: To describe the trajectory of sleep oximetries in infants with PRS.

Methods: Infants in our service have multiple sleep oximetries at regular intervals in the first months of life.  Infants with OSA and PRS are managed in our service with a nasopharangeal airway (NPA).  Serial oximetries are undertaken with and without NPA to follow progression.  Typically an Oxygen Desaturation Index 4% (ODI4) over 20 would result in replacement of the NPA.

We report data on ODI4 results for infants born from 2018 ? 2021.  We modelled the trajectory of ODI4 using restricted cubic splines and quantile regression to produce a centile chart of ODI 4 for the first 6 months of age, using studies without NPAs. 

Results: We report data from 157 sleep oximetries undertaken in 25 infants.  We construct centile charts using this data from age 0 ? 6 months (see fig. 1).  In the first 50 days of life the 75th centile of ODI4 was around 20, declining to less than 10 after 150 days.

Conclusion: There is a wide range of ODI4 results which represent degrees of obstructive apnoea.  These charts could help in airway adjunct and respiratory support decision making.