Smoking in pregnancy is a key factor for sudden infant death among Māori

A study of Samoan, Tongan, Cook Island Māori, and Niuean infant care practices in the Growing Up in New Zealand study

BACKGROUND

Despite a low rate of infant mortality, Aotearoa New Zealand has a high rate of Sudden Unexpected Death in Infants (SUDI), with disproportionate impact for Pacific infants. This study explored the infant care practices, factors and relationships associated with increased risk of SUDI amongst Tongan, Samoan, Cook Islands Māori, and Niuean mothers in New Zealand, to inform evidence-based interventions for reducing the incidence of SUDI for Pacific families and their children.

METHODS

Analysis comprised of data collected in 2009-2010 from 1089 Samoan, Tongan, Cook Islands Māori and Niuean mothers enrolled in the Growing Up in New Zealand longitudinal cohort study. The sleeping environment (bed-sharing and sleep position) of the infants was assessed at 6 weeks. Multivariable logistic regression analysis were conducted, controlling for sociodemographic factors to explore the association between selected maternal and pregnancy support and environment factors and the sleeping environment for infants.

RESULTS

Mothers who converse in languages other than English at home, and mothers who consulted alternative practitioners were less likely to follow guidelines for infant sleeping position. Similarly language, smoking, alcohol, household dwelling, crowding and access to a family doctor or GP were associated with mothers following guidelines for bed-sharing.

CONCLUSION

The impact of SUDI on Pacific infants may be lessened or prevented if communication about risk factors is more inclusive of diverse ethnic, cultural worldviews, and languages. Societal structural issues such as access to affordable housing is also important. This research suggests a need for more targeted or tailored interventions which promote safe sleeping and reduce rates of SUDI in a culturally respectful and meaningful way for Pasifika communities in Aotearoa, New Zealand.

Regional variation in sudden unexpected death in infancy in New Zealand

AIM

To estimate the relative risk of sudden unexpected death in infancy (SUDI) by district health board (DHB) in New Zealand after adjustment for socio-economic deprivation, ethnicity and other demographic factors.

METHODS

We conducted a population-based cohort study using data from the Integrated Data Infrastructure, a large research database containing linked data from a range of government agencies. The study population was all live births and their mothers in New Zealand from 2012 to 2018. The exposure of interest was DHB. The outcome was SUDI.

RESULTS

There were 418 068 live births in New Zealand from 2012 to 2018, and of these 415 401 (99.4%) had valid DHB data. There was considerable variation in the proportion of infants in each DHB living in the most deprived decile varying from 4.5% in Nelson, West Coast and Canterbury to 29.7% in Counties Manukau. There were 267 SUDI cases, giving an overall rate of 0.64/1000 live births during the study period (2012-2018). The SUDI rate varied from 1.11/1000 in Northland to 0.30/1000 in Waitemata and Auckland. Counties Manukau had the largest number of deaths (n = 54; rate = 1.08/1000). Five DHB regions had increased risk of SUDI compared to the reference group but, after adjustment, no DHB was significantly increased.

CONCLUSIONS

This study found that there is marked variation in SUDI risk by DHB, but this is explained by socio-economic and demographic variation within DHBs. This study emphasises the importance of the contribution of social determinants of health to SUDI.

Maternal mental health and substance use disorders in sudden unexpected death in infancy using routinely collected health data in New Zealand, 2000-2016

BACKGROUND

Mortality from sudden unexpected death in infancy (SUDI) has declined dramatically since the 'Back to Sleep' campaign. Deaths now are more prevalent in those with socioeconomic disadvantage. The investigation of SUDI frequently identifies parents that have mental health or drug, alcohol and addiction problems.

AIMS

To estimate the prevalence of maternal mental health and substance use disorders and assess the magnitude of their risk for SUDI.

METHODS

We conducted a population-based cohort study using data from the Integrated Data Infrastructure (IDI), a large research database containing linked data from a range of government agencies. The study population was all live births and their mothers in New Zealand from 2000 to 2016. The exposures of interest were maternal mental health problems and maternal substance use disorders in the year prior to the birth. The outcome was deaths from SUDI.

RESULTS

The total population was 1086 504 live births and of these 1078 811 (99.3%) were able to be linked to other data sets within the IDI. The prevalence of maternal mental health problems in the total population was 5.2% and substance use disorder was 0.7%. There were 42 deaths from SUDI (0.75/1000) that were exposed to maternal mental illness and 864 deaths (0.84/1000) that were not exposed (adjusted relative risk (aRR)=1.23, 95% CI 0.90 to 1.68). There were 21 deaths from SUDI (2.67/1000) that were exposed to maternal substance use disorders and 885 (0.83/1000) that were not exposed (aRR=1.82, 95% CI 1.17 to 2.83).

CONCLUSIONS

Maternal substance use disorders, but not maternal mental health problems, in the year prior to the child's birth was associated with an increased risk of SUDI. However, the numbers that are affected are small and the effect size moderate. This group of women should receive additional SUDI prevention services and Safe Sleep advice.

Infant Sleep Hazards and the Risk of Sudden Unexpected Death in Infancy

OBJECTIVE

To examine the effects of infant sofa-sleeping, recent use by caregivers of alcohol, cannabis, and/or other drugs, and bed type and pillows, on the risk of sudden unexpected death in infancy (SUDI) in New Zealand.

STUDY DESIGN

A nationwide prospective case-control study was implemented between March 2012 and February 2015. Data were collected during interviews with parents/caregivers. "Hazards" were defined as infant exposure to 1 or more of sofa-sleeping and recent use by caregivers of alcohol, cannabis, and other drugs. The interaction of hazards with tobacco smoking in pregnancy and bed sharing, including for very young infants, and the difference in risk for Māori and non-Māori infants, also were assessed.

RESULTS

The study enrolled 132 cases and 258 controls. SUDI risk increased with infant sofa-sleeping (imputed aOR [IaOR] 24.22, 95% CI 1.65-356.40) and with hazards (IaOR 3.35, 95% CI 1.40-8.01). The SUDI risk from the combination of tobacco smoking in pregnancy and bed sharing (IaOR 29.0, 95% CI 10.10-83.33) increased with the addition of 1 or more hazards (IaOR 148.24, 95% CI 15.72-1398), and infants younger than 3 months appeared to be at greater risk (IaOR 450.61, 95% CI 26.84-7593.14).

CONCLUSIONS

Tobacco smoking in pregnancy and bed sharing remain the greatest SUDI risks for infants and risk increases further in the presence of sofa-sleeping or recent caregiver use of alcohol and/or cannabis and other drugs. Continued implementation of effective, appropriate programs for smoking cessation, safe sleep, and supplying safe sleep beds is required to reduce New Zealand SUDI rates and SUDI disparity among Māori.

A ten-year retrospective case review of risk factors associated with sleep-related infant deaths

AIM

The study aimed to identify risk factors associated with sleep-related deaths of infants (0-24 months) in the province of Manitoba, Canada, between January 2009 and December 2018.

METHODS

A systematic retrospective case review of autopsies and administrative records in Manitoba between 2009 and 2018.

RESULTS

A total of 145 infants died in cases where unsafe sleep environments were known to have contributed to or resulted in their death and where no explained medical causes were identified. Where data complete, all infants had at least one known risk factor for sleep-related deaths, and 96% had multiple. The most common risk factors increased over time and included objects in the sleeping environment (90% of cases), not approved sleep surfaces (77%) and bedsharing (50%). Indigenous infants, infants of young mothers and infants in low-income neighbourhoods are overrepresented. Risk factors for Indigenous infants differed from cases involving non-Indigenous infants.

CONCLUSION

A high proportion of sleep-related infant deaths were associated with not approved sleep surfaces and bedsharing, especially for infants under one year. Families in low-income neighbourhoods, Indigenous families and families with young mothers were disproportionately affected by sleep-related infant deaths. There is a need to enhance messaging and smoking cessation messaging in Indigenous communities to prevent sleep-related deaths.

Pēpē-infant sleep practices and sudden unexpected death in infancy in Aotearoa New Zealand

OBJECTIVE

To explore pēpē [infant] sleep practices and the key motivators among selected Māori and non-Māori māmā [mothers] in Auckland, New Zealand, in relation to the risk of sudden unexpected death in infancy (SUDI).

METHODS

Qualitative research underpinned by a kaupapa Māori cultural framework was undertaken. In-depth face-to-face interviews occurred in the homes of māmā with young pēpē born in Counties Manukau, Auckland. Interview transcripts were analyzed using general purpose thematic analysis.

RESULTS

Thirty māmā participated, including 17 Māori. Two-thirds of māmā reported previous or current bed sharing. The fundamental human need for adequate sleep motivated half the māmā in the present study, and especially Māori māmā, to bed share. The second most common reason given was closeness and convenience. This was followed by breastfeeding, which was cited as a reason by Māori māmā only. These findings were interpreted in terms of intrinsic fear, culture, and māmā deployment of knowledge.

CONCLUSION

Service providers are encouraged to respond to the lived experiences and cultural realities, values, and beliefs of māmā when designing and delivering effective SUDI prevention interventions. Innovative approaches for providing structured and opportunistic, culturally appropriate education and support around safe sleep are likely to be well-received by māmā and their whānau [family/ies].

Prevalence of risk factors for sudden infant death among Indigenous and non-Indigenous people in Australia

AIM

To examine differences in the prevalence of risk factors for sudden unexpected death in infancy (SUDI) between Aboriginal and Torres Strait Islander and non-Indigenous infants.

METHODS

A retrospective cohort study of SUDI in Queensland during 2010-2014 examined exposure to SUDI risk factors, to identify factors accounting for higher SUDI mortality among Indigenous infants. A multistage algorithm was applied to linked data to determine Indigenous status.

RESULTS

There were 228 SUDI, of which Indigenous infants comprised 26.8%. The Indigenous SUDI rate was 2.13/1000 live births compared to 0.72/1000 for non-Indigenous. The disparity between Indigenous and non-Indigenous SUDI was accounted for by surface sharing (OR = 2.93 95% CI = 1.41, 6.07), smoking (OR = 2.49, 95% CI = 1.13, 5.52), and a combination of background antenatal and sociodemographic factors (inadequate antenatal care [OR = 6.93, 95% CI = 2.20, 21.86], young maternal age at first birth [OR = 4.02, 95% CI = 1.49, 10.80] and outer regional [OR = 3.03, 95% CI = 1.37, 6.72] and remote locations [OR = 11.31, 95% CI = 3.47, 36.83]).

CONCLUSION

Culturally responsive prevention efforts, including wrap-around maternity care and strategies that reduce maternal smoking and promote safer yet culturally acceptable ways of surface sharing, may reduce Indigenous SUDI mortality.

The Role of Maternal Smoking in Sudden Fetal and Infant Death Pathogenesis

Maternal smoking is a risk factor for both sudden infant death syndrome (SIDS) and sudden intrauterine unexplained death syndrome (SIUDS). Both SIDS and SIUDS are more frequently observed in infants of smoking mothers. The global prevalence of smoking during pregnancy is 1.7% and up to 8.1% of women in Europe smoke during pregnancy and worldwide 250 million women smoke during pregnancy. Infants born to mothers who smoke have an abnormal response to hypoxia and hypercarbia and they also have reduced arousal responses. The harmful effects of tobacco smoke are mainly mediated by release of carbon monoxide and nicotine. Nicotine can enter the fetal circulation and affect multiple developing organs including the lungs, adrenal glands and the brain. Abnormalities in brainstem nuclei crucial to respiratory control, the cerebral cortex and the autonomic nervous system have been demonstrated. In addition, hypodevelopment of the intermediolateral nucleus in the spinal cord has been reported. It initiates episodic respiratory movements that facilitate lung development. Furthermore, abnormal maturation and transmitter levels in the carotid bodies have been described which would make infants more vulnerable to hypoxic challenges. Unfortunately, smoking cessation programs do not appear to have significantly reduced the number of pregnant women who smoke.