A decade of tragic consistency: Analysing the sudden unexpected death in infancy rates in Aotearoa New Zealand

In 2019, the most recent data available, 46 babies died from SUDI, up from 37 deaths the previous year. Over the span of a decade, aside from a decline in death rates between 2010 and 2012, the rates have remained relatively steady without significant improvement, even following the introduction of the National SUDI prevention programme by the Government in 2017.

EHINZ’s Senior Intelligence Analyst and report author Helene Marsters notes significant disparities among affected groups, with Pacific and Māori babies experiencing five times the rate of SUDI compared to other babies.

“Between 2015 to 2019, Māori babies had a rate of 1.4 per 1,000 live births and Pacific babies had a rate of 1.5 per 1,000 live births. In 2019, of the 46 deaths, 29 were Māori and eight were Pacific. The data also shows consistently higher rates of SUDI among babies born to younger mothers.”

Mothers younger than 25 years old were disproportionately represented in the results, with maternal age groups between 20 and 24, as well as those below 20, showing a rate of 1.5 SUDI deaths per 1,000 live births. Exposure to second-hand smoke was found to significantly increase the risk of SUDI in infants, with maternal smoking doubling the risk.

The data also highlights socioeconomic disparities, with babies in the most deprived areas (quintile five) experiencing a significantly higher SUDI rate of 1.5 per 1,000 live births compared to other quintiles.

“Babies in the most deprived areas of Aotearoa New Zealand had over seven times the rate of SUDI compared to those in the least deprived areas. These findings underscore the need for targeted interventions and support systems to address underlying social determinants contributing to these disparities in infant mortality,” Ms Marsters says.

Districts with the highest SUDI rates from 2015 to 2019 were Tairāwhiti and Whanganui, both with a rate of 1.6 per 1,000 live births.

The report, based on the most recent data available from the Fetal and Infant Deaths web tool published by Health New Zealand – Te Whatu Ora in December 2023, focused on deaths of children under one year old, with underlying causes including sudden infant death syndrome, other sudden death with unknown causes, accidental suffocation and strangulation in bed, inhalation of gastric contents, unattended death and respiratory tract obstruction due to food inhalation or ingestion.

EHINZ, based within Te Kunenga ki Pūrehuroa Massey University’s College of Health, is funded by the Ministry of Health to monitor and provide intelligence on the effect of the environment on health of New Zealanders.

For further details, the full SUDI report can be accessed here.