Vaping emerges as new concern in New Zealand infant deaths

Maternal vaping is emerging as a potential risk factor for Sudden Unexpected Death in Infancy (SUDI), according to New Zealand researchers, who say their findings highlight the need to reassess public health messaging around vaping in pregnancy and bed sharing.

Smoking during pregnancy by mothers and sharing the bed with their baby are recognised major risk factors for SUDI, especially when they occur together. In New Zealand smoking in pregnancy has decreased, but SUDI rates remain the same.

A recent study of a series of 101 SUDI deaths in New Zealand during 2022 and 2023 had detailed information about maternal nicotine exposure and the infant's sleep environment for 66 cases.

Findings showed that smoking and/or vaping was reported in nearly three-quarters of these cases, while nearly 70 percent of infants had died while directly bed sharing. Maternal vaping was reported in half of the SUDI cases involving direct bed sharing, compared with one in five cases where direct bed sharing was not reported.

“The interaction between maternal smoking and bed sharing is well established,” says lead author Professor Ed Mitchell, of Waipapa Taumata Rau, University of Auckland.

“What is new and concerning is that vaping may be showing a similar pattern of risk as smoking, especially when combined with bed sharing. This raises the possibility that the effects of nicotine itself, rather than how nicotine is delivered, may be contributing to infant vulnerability.” 

The researchers stress that the study does not prove that vaping causes SUDI.

“Uncertainty is not reassurance,” says co-author Professor Barry Taylor, of the University of Otago, Ōtākou Whakaihu Waka. “When the possible consequence is an infant death, a precautionary approach is warranted while the evidence develops.”

The researchers say the findings raise a fundamental question about current pregnancy advice.

“Vaping has been widely approached as a safer alternative to smoking and a smoking cessation aid, including in pregnancy. Our findings suggest we need to consider all nicotine exposure during pregnancy, particularly when it is combined with bed sharing,” says Professor Mitchell.

In a related policy analysis published in the journal Acta Paediatrica, the same authors argue that pregnancy requires a different approach to nicotine policy from that used for non-pregnant adults.

“Nicotine crosses the placenta, reduces foetal blood flow and lowers birthweight,” explains Professor Taylor. “We suspect that vaping may also produce the same infant ‘arousal defect’ seen with tobacco exposure.”

The researchers recommend a pregnancy-specific approach with being nicotine-free as the goal, and coordinated support for women to achieve this across addiction services, pregnancy care, SUDI prevention and family support.

“Every woman who vapes or smokes during pregnancy needs support that meets them where they are in terms of their circumstances and confidence,” says co-author Stephanie Cowan, of Change for Our Children. “The aim is to help every woman move towards cessation as early as possible in pregnancy, because that is how both mother and infant are protected.”

In the SUDI cases studied, 84.8 percent of deaths occurring during direct bed sharing involved maternal smoking or vaping.

The researchers say more research is needed urgently to establish the specific risks associated with vaping during pregnancy. In the meantime, they argue that vaping, like smoking, should be discouraged in pregnancy and women should be supported to be nicotine-free as early as possible as the new health norm.