Smoking in pregnancy and bed sharing, a fatal combination

Abstract

Smoking in pregnancy and bed sharing, a fatal combinationOver the last three decades, epidemiological research in New Zealand has produced results that really have made a difference for our understanding of how to reduce the risk of cot death. Almost 30 years ago, the New Zealand Cot Death Study convincingly demonstrated that sleeping prone, smoking and bottle-feeding were factors that increased the risk of cot death (1). Further analyses showed that also sleeping in the same bed as an adult increased the risk of cot death, particularly among infants of mothers who smoked (2). Now, the New Zealand Sudden Unexpected Death in Infancy (SUDI) Nationwide Study (2012)(2013)(2014)(2015) has reinvestigated the risk factors identified in the New Zealand Cot Death Study and specifically focused on the sleep environment (3).In New Zealand, there is a high incidence of SUDI in the indigenous population, the M aoris (4). SUDI rates for M aori have decreased, partly due to a successful Safe Sleep Programme (4), but remain higher than for the non-M aori population. In this issue of Acta Paediatrica, MacFarlane et al. (5) address the question why the SUDI incidence is so high among M aoris. Half of the SUDI cases in New Zealand between 2012 and 2015 were M aori, despite that M aori comprise less than a third of live births in the country. The SUDI mortality rate for M aori was 1.4 per 1000 live births compared to 0.5/1000 for non-M aori. The overall SUDI rate was 0.8/1000 (5).The MacFarlane study finds that a combination of smoking in pregnancy and bed sharing leads to an increased SUDI risk for M aori as well as for non-M aori infants. As such, the risk factors for SUDI, and the magnitude of the risks, are the same regardless of ethnicity. However, M aori infants are exposed more frequently to both behaviours because of a higher smoking rate among M aori women. Thus, the higher smoking rate explains the high incidence of SUDI among the M aoris.

Highlights in this issue

“…However, the Maori infants were exposed to both behaviours more frequently. Göran Wennergren comments on the findings.…”