BMJ Open first published this paper, based on unique NCMD data, which looks at how risk factors for Sudden Infant Death Syndrome (SIDS) have changed over the last 30 years.

This paper investigates the background characteristics and risk factors in the sleeping environment associated with sudden infant death syndrome (SIDS), and compares the comprehensive NCMD data for 2020 with a combined analysis of two case-control studies conducted in 1993–1996 and 2003–2006.

It finds that the 138 children dying due to SIDS in 2020 were, on average, younger, born at lower weight and more likely to have been born preterm than the 402 children who died in 1993–1996 and 2003–2006. A predominance of children from socioeconomically deprived families, male children and high levels of maternal smoking were all risk factors that were evident across all three decades.

Despite action to promote safe sleeping over the last three decades, the study finds that there was no significant change in the proportion of infants who were put down and found prone. In 2003–2006 half the deaths occurred while sleeping next to an adult, and this remained unchanged in 2020; for the vast majority (90%), this was in hazardous circumstances (adult had consumed alcohol, smoked, slept on a sofa, or the infant was premature or low birth weight and less than 3 months old).

It is hoped that this new insight could enable a more targeted approach to emphasise safe sleep messages for vulnerable families, to encourage sleeping infants on their back and proactive planning of infant sleep when there are disruptions to the normal routine, in particular to avoid hazardous co-sleeping.