Objective:Cleft palate (CP) can affect breathing, leading to sleep-disordered breathing (SDB). Sleep position can affect SDB, but the optimum sleep position for infants with CP is unknown. We aimed to determine the design of a pragmatic study to investigate the effect of the 2 routinely advised sleep positions in infants with CP on oxygen saturations.Design:A multicentered observational cohort.Setting:Four UK-based cleft centers, 2 advising supine- and 2 side-lying sleep positions for infants with CP.Participants:Infants with isolated CP born July 1, 2015, and December 31, 2016. Of 48 eligible infants, 30 consented (17 side-lying; 13 supine).Interventions:Oxygen saturation (SpO2) and end-tidal carbon dioxide (ETCO2) home monitoring at age 1 and 3 months. Qualitative interviews of parents.Outcome Measures:Willingness to participate, recruitment, retention, and acceptability/success (>90 minutes recording) of SpO2 and ETCO2 monitoring.Results:SpO2 recordings were obtained during 50 sleep sessions on 24 babies (13 side-lying) at 1 month (34 sessions >90 minutes) and 50 sessions on 19 babies (10 side-lying) at 3 months (27 sessions >90 minutes). The ETCO2 monitoring was only achieved in 12 sessions at 1 month and 6 at 3 months; only 1 was >90 minutes long. The ETCO2 monitoring was reported by the majority as unacceptable. Parents consistently reported the topic of sleep position in CP to be of importance.Conclusions:This study has demonstrated that it is feasible to perform domiciliary oxygen saturation studies in a research setting and has suggested that there may be a difference in the effects of sleep position that requires further investigation. We propose a study with randomization is indicated, comparing side-lying with supine-lying sleep position, representing an important step toward better understanding of SDB in infants with CP.