Sudden unexpected death in infancy (SUDI)

Factsheets and Metadata

Factsheet: Sudden unexpected death in infancy (June 2022) View interactive report Download report PDF
Metadata: Sudden unexpected death in infancy (June 2022) Download report PDF

Maternal smoking doubles the risk of SUDI

Infants (under one year old) exposed to second-hand smoke are at higher risk of sudden unexpected death in infancy (SUDI) [1]. Having a mother who smokes also doubles their risk of dying from SUDI [2].

In 2002–2010, New Zealand had a high SUDI rate compared with other developed countries. New Zealand’s SUDI rate was 1.01 deaths per 1,000 live births, compared with 0.95 in the United States, 0.60 in Japan, 0.50 in Australia, 0.45 in England and Wales, and 0.19 in the Netherlands [3]. SUDI was the primary cause of death due to second-hand smoke in New Zealand in 2010. An estimated six children died of SUDI (6% of all attributable deaths) from second-hand smoke exposure that same year [4].

Information about this data 

Sudden unexpected death in infancy (SUDI)

Source: Ministry of Health [5]

Definition: Deaths in children aged under one year of age (<1 year old) with an underlying cause of death in the following ICD-10AM codes: R95, R96, R98, R99, W75, W78, W79. Rates are presented per 1000 live births.

For more information, see the metadata sheet


1. US Department of Health and Human Services. 2007. Children and Secondhand Smoke Exposure. Excerpts from The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Coordinating Center for Health Promotion, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health. 

2. Anderson HR, & Cook, D. 1997. Passive smoking and sudden infant death syndrome: review of the epidemiological evidence. Thorax, 52, 1003-1009.

3. Taylor BJ, Garstang J, Engelberts A et al. 2015. International comparison of sudden unexpected death in infancy rates using a newly proposed set of cause-of-death codes. Archives of Disease in Childhood 100(11): 1018–23. DOI: 10.1136/archdischild-2015-308239.

4. Mason K, Borman B. 2016. Burden of disease from second-hand smoke exposure in New Zealand. New Zealand Medical Journal 129(1432): 16–25.

5. Ministry of Health. 2021. Fetal and Infant Deaths web tool. Wellington: Ministry of Health.

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