Professor Ed Mitchell
SUDI Academic Expert
Auckland University

Ed Mitchell qualified at St George’s Hospital Medical School in London and has worked in the UK, Zambia and New Zealand.

He was the Cure Kids Professor of Child Health Research at the University of Auckland from 2001 to 2015 and is now a Professorial Research Fellow. He has published over 400 original papers, particularly on the epidemiology of sudden infant death syndrome (SIDS). He was awarded a Doctor of Science for his work on “The Epidemiology and Prevention of SIDS” by the University of London. He has received several awards for his landmark studies of SIDS and in 2009 was made a fellow of the Royal Society of New Zealand.

Professor Ed Mitchell answers questions from the community.

Should we be putting a hat on baby to sleep at night now its’ got cold?

Questions relating to type and amount of baby clothing are frequent. In the original New Zealand Cot Death Study (1987-1990) baby hats (e.g. beanies and bonnets) were used in 8.3% of cases and 5.2% of controls. In the Nationwide SUDI Study hats were used by 4.8% of cases and 3.9% of controls. These differences are small and not statistically significant.

In infants the surface area of the head and neck is 20% of their total body area (compared with just 9% in adults). Heat loss can be considerable, so in cold conditions a hat will reduce this. This may prevent the baby getting cold and uncomfortable. But it doesn’t affect the risk of SUDI.

Head covering increases the risk of SUDI, but this does not refer to hats; it refers to baby’s head being covered with blankets. A meta-analysis of 10 studies found the prevalence in cases was 24.6% and 3.2% among controls. This suggests head covering by blankets is a modifiable risk factor associated with SIDS deaths and has led to the UK recommendation to place baby at the foot of the bed (“Feet to foot”). Theoretically this might prevent babies kicking the blankets over their heads, but there isn’t much evidence to support that this happens, which is why we do not emphasise this in New Zealand.

  • hat
  • cold
  • baby clothing