Elsevier

Legal Medicine

Volume 15, Issue 3, May 2013, Pages 115-121
Legal Medicine

Maternal smoking and increased risk of sudden infant death syndrome: A meta-analysis

https://doi.org/10.1016/j.legalmed.2012.10.007Get rights and content

Abstract

Maternal smoking is detrimental to the development of fetuses and neonates. This meta-analysis was performed to measure the accumulated association of sudden infant death syndrome (SIDS) risk with both prenatal and postnatal maternal smoking. The odds ratio (OR) corresponding to the 95% confidence interval (CI) was used to assess the associations between maternal smoking and SIDS risk. The statistical heterogeneity among studies was assessed with the Q-test and I2 statistics. The data for this meta-analysis were available from 35 case-control studies. The prenatal and postnatal maternal smoking was associated with a significantly increased risk of SIDS (OR = 2.25, 95% CI = 2.03–2.50 for prenatal maternal smoking analysis, and OR = 1.97, 95% CI = 1.77–2.19 for postnatal maternal smoking analysis, respectively) by random effects model. After stratified analyses, regardless of prenatal or postnatal smoking, heavy cigarette consumption increased the risk of SIDS and significantly elevated SIDS risk was found to be associated with co-sleeping with postnatal smoking mothers. Our results suggested that maternal smoking were associated with elevated SIDS risk, the effects were dose-dependent. In addition, SIDS risk was significantly increased in infants co-sleeping with postnatal smoking mothers.

Introduction

SIDS is the sudden and unexpected death of a child below 1 year of age that remains unexplained after a thorough investigation of the circumstances, family history, a pediatric examination and a full autopsy [1]. Most SIDS deaths happen within the first 8 months of life, with most around 3–4 months and fewest in the first month [2]. A number of studies have revealed the possible risk factors for SIDS such as male gender, premature birth, prone sleeping, soft bedding, whereas breastfeeding, room sharing, sleeping sack and dummy use were found to have the potential of a protective effect [2], [3], [4], [5], [6], [7], [8], [9]. Epidemiological studies have suggested that perinatal events could play an important role. However, information regarding to maternal smoking has been inconsistent. The authors of a meta-analysis published in 1997 concluded that maternal smoking doubles the risk of sudden infant death syndrome [10]. Considering a single study might have been underpowered to detect the overall effects and previous authors defined SIDS loosely. A quantitative synthesis of the accumulated data from different studies was deemed important to provide evidence on the association of maternal smoking with SIDS risk. So, we carried out this meta-analysis on all published case-control studies to estimate the overall SIDS risk of maternal smoking and to quantify heterogeneity between the individual studies as well as to investigate the existence of potential publication bias.

Our meta-analysis was performed with the following hypotheses: (1) both prenatal and postnatal maternal smoking are associated with increased SIDS risk, (2) SIDS risk associated with maternal smoking is dose-dependent, and (3) infants co-sleeping with smoking mothers have a higher risk of SIDS.

Section snippets

Publication search and inclusion criteria

We searched the PubMed and CNKI (China National Knowledge Infrastructure) databases for all articles within a range of published years from 1990 to 2011 on the association between maternal smoking and SIDS risk (last search was update 30th December 2011). The following terms were used in this search: “sudden infant death” and “smoking”. In order to identify the relevant publications, the references cited in the research papers were also scanned. Combining searches resulted in 664 abstracts (

Characteristics of studies

Out of a total of 681 articles identified initially, 624 articles were screened. Of these, 498 articles concerned topics not relevant to this study, and 35 case-control studies with 31,040 cases and 5,956,030 controls met the inclusion criteria for this study. The trials were conducted in France, Sweden, England, New Zealand, Australia, America, Hungary, Germany, Netherlands, Norway, Scandinavian countries, Brazil, and Denmark between 1992 and 2011. Study characteristics are summarized in Table

Discussion

In this study, we performed a meta-analysis of the association between maternal smoking and risk for SIDS based on 35 case-control studies for which information was available. That included 23 published manuscripts available for prenatal maternal smoking analysis and 18 published manuscripts available for postnatal maternal smoking analysis. Our meta-analysis provided evidence that both prenatal and postnatal maternal smoking was associated with increased SIDS risk. Moreover, heavy cigarettes

References (60)

  • M.P. l’Hoir et al.

    Case-control study of current validity of previously described risk factors for SIDS in The Netherlands

    Arch Dis Childhood

    (1998)
  • E.A. Mitchell

    Recommendations for sudden infant death syndrome prevention: a discussion document

    Arch Dis Childhood

    (2007)
  • The changing concept of sudden infant death syndrome: diagnostic coding shifts, controversies regarding the sleeping environment, and new variables to consider in reducing risk

    Pediatrics

    (2005)
  • M.M. Vennemann et al.

    Sleep environment risk factors for sudden infant death syndrome: the German sudden infant death syndrome study

    Pediatrics

    (2009)
  • M.M. Vennemann et al.

    Modifiable risk factors for SIDS in Germany: results of GeSID

    Acta Paediatr

    (2005)
  • H.R. Anderson et al.

    Passive smoking and sudden infant death syndrome: review of the epidemiological evidence

    Thorax

    (1997)
  • B. Alm et al.

    A case-control study of smoking and sudden infant death syndrome in the Scandinavian countries, 1992 to 1995. The Nordic epidemiological SIDS study

    Arch Dis Childhood

    (1998)
  • T. Dwyer et al.

    Tobacco smoke exposure at one month of age and subsequent risk of SIDS – a prospective study

    Am J Epidemiol

    (1999)
  • D. Getahun et al.

    Maternal and obstetric risk factors for sudden infant death syndrome in the United States

    Obstet Gynecol

    (2004)
  • B. Alm et al.

    Caffeine and alcohol as risk factors for sudden infant death syndrome. Nordic epidemiological SIDS study

    Arch Dis Childhood

    (1999)
  • M. Vennemann et al.

    Do risk factors differ between explained sudden unexpected death in infancy and sudden infant death syndrome?

    Arch Dis Childhood

    (2007)
  • A.K. Daltveit et al.

    Sociodemographic risk factors for sudden infant death syndrome: associations with other risk factors. The Nordic epidemiological SIDS study

    Acta Paediatr

    (1998)
  • B. Haglund et al.

    Cigarette smoking as a risk factor for sudden infant death syndrome: a population-based study

    Am J Public Health

    (1990)
  • P.S. Blair et al.

    Smoking and the sudden infant death syndrome: results from 1993–5 case-control study for confidential inquiry into stillbirths and deaths in infancy. Confidential enquiry into stillbirths and deaths regional coordinators and researchers

    BMJ

    (1996)
  • S.M. Williams et al.

    Are risk factors for sudden infant death syndrome different at night?

    Arch Dis Childhood

    (2002)
  • P.J. Fleming et al.

    Pacifier use and sudden infant death syndrome: results from the CESDI/SUDI case control study. CESDI SUDI research team

    Arch Dis Childhood

    (1999)
  • J.P. Higgins et al.

    Quantifying heterogeneity in a meta-analysis

    Stat Med

    (2002)
  • N. Mantel et al.

    Statistical aspects of the analysis of data from retrospective studies of disease

    J Nat Cancer Inst

    (1959)
  • C.B. Begg et al.

    Operating characteristics of a rank correlation test for publication bias

    Biometrics

    (1994)
  • W. Hofhuis et al.

    Adverse health effects of prenatal and postnatal tobacco smoke exposure on children

    Arch Dis Childhood

    (2003)
  • Cited by (109)

    • My quitting stories: A qualitative study exploring Aboriginal women's experiences of smoking cessation and preventing relapse in the context of pregnancy

      2023, Women and Birth
      Citation Excerpt :

      Smoking cessation messages that pregnant and postpartum Aboriginal women receive appear to lack consistency and clarity and tend not to focus on long-term abstinence [10]. Second-hand smoke exposure in infancy is associated with increased risk of respiratory, neurological and immunological morbidity [11], sudden infant death syndrome [12], ear infections[11], and adverse behavioural and cognitive outcomes [11]. Thus, relapse to smoking postnatally among Aboriginal women who have previously quit has enduring implications for their babies and poses risks of tobacco-related morbidity and mortality for themselves [13].

    • Cigarettes: A toxic lifelong cycle

      2023, Encyclopedia of Child and Adolescent Health, First Edition
    • Unique effects of nicotine across the lifespan

      2022, Pharmacology Biochemistry and Behavior
      Citation Excerpt :

      Gestational nicotine exposure also impacts the developing brain at doses that do not delay general growth (Slotkin, 1998), which can be observed through motor, sensory, cognitive, and behavioral deficits in infants and toddlers (Ernst et al., 2001; Fergusson et al., 1998; Fuentes-Cano et al., 2020; Gusella and Fried, 1984; Lichtensteiger et al., 1988; Weissman et al., 1999; Zeid et al., 2018). Smoking during pregnancy is now considered to be the primary cause of sudden infant death syndrome, resulting from compromised development of cardiac and respiratory brainstem centers (Slotkin and Seidler, 2011; Vivekanandarajah et al., 2019; Zhang and Wang, 2013). Additionally, in utero exposure to nicotine produces decreased synaptic plasticity and developmental effects on the medial prefrontal cortex and nucleus accumbens in rodents, which is observed through attention-deficit/hyperactivity disorder, conduct problems, depression, anxiety, externalizing behavior, and substance use in the offspring (Table 1; Franke et al., 2008; Dwyer et al., 2019).

    View all citing articles on Scopus
    1

    These authors contributed equally to this work.

    View full text