Maternal smoking and increased risk of sudden infant death syndrome: A meta-analysis
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.
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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
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2023, Women and BirthCitation 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].
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2023, Encyclopedia of Child and Adolescent Health, First EditionUnique effects of nicotine across the lifespan
2022, Pharmacology Biochemistry and BehaviorCitation 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).
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These authors contributed equally to this work.