Background Accidental suffocation during sleep, leading to death, has been described as due to overlay or wedging of infants, particularly in a bed-sharing situation. Bed sharing is a risk factor for sudden infant death syndrome but the mechanism of death is not clearly defined. Accidental suffocation may be one such mechanism.

Objective To describe accidental suffocation deaths during sleep in New Zealand between 2002 and 2009.

Design The New Zealand mortality database, which holds data collected by the Child Youth Mortality Review Committee and the Perinatal and Maternal Mortality Review Committee, was searched for potential deaths by accidental suffocation in infants less than 1 year of age. Deaths underwent a detailed analysis by demographic data and qualitative report.

Results There were 48 deaths due to accidental suffocation between 2002 and 2009 in New Zealand, equating to a rate of 0.10 deaths per 1000 live births. The most common age at death was 1 month or under (n=11, 23%). Deaths were due to overlay (n=30, 63%) or wedging (n=18, 37%) and two-thirds (n=34, 71%) were in a bed-sharing situation. A quarter of deaths (n=12, 25%) occurred in makeshift bedding arrangements, some of which were away from home.

Conclusions Accidental suffocation in bed was responsible for 48 preventable deaths. Prevention of these accidental deaths needs to focus on supporting changes in family behaviour with safety messages that are consistent, persistent and disseminated widely.