Present or Absent: Risks and protective factors of sudden infant death syndrome (SIDS) in the Zambian context

Present or Absent: Risks and protective factors of sudden infant death syndrome (SIDS) in the Zambian context | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Present or Absent: Risks and protective factors of sudden infant death syndrome (SIDS) in the Zambian context Ethan M. Zulu, Lawrence Mwananyanda, Rachel C. Pieciak, Leah S. Forman, and 10 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6427293/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Despite a reduction in Sudden Unexplained Infant Death (SUID) in high-income countries, the incidence of SUID and the prevalence of its risk and protective factors remain poorly understood in Zambia due to limited research. The aim of our study was to describe the infant sleep positions and sleep environments in an urban Zambian population to gain a better understanding of the modifiable risk factors for SUID. Methods Data from the Zambian Infant Cohort Study (ZICS), a prospective birth cohort, were collected to describe infant sleep practices in Chawama, a densely populated peri-urban community in Lusaka, Zambia. During the 20-week study visit a structured questionnaire was administered to obtain data about the sleeping and environmental risks associated with SUID. Results Data were collected from 596 caregivers and 605 infants. Only 6.4% of caregivers did attain an education beyond secondary school, and a significant proportion of infants (20.2%) had low birth weights, with 10.7% of infants confirmed by ultrasound as preterm. Furthermore, 96.5% of infants were placed to sleep on their side or in a prone position, and 98.2% of infants shared a sleep surface with their caregiver. Breastfeeding, a protective factor, was highly prevalent, with 90.2% of infants receiving some form of breastfeeding at the 24-week visit. Conclusion The results of this study show that both modifiable (bed-sharing and prone sleep position) and non-modifiable risk factors (low birthweight and prematurity) of SUID are prevalent in this low socioeconomic setting in Zambia. Public health strategies to prevent SUID will need to be innovative and culturally congruent in addressing modifiable risks, such as bedsharing, in settings where there is a lack of space. Trial registration: Trial number: 1R01HD094650 Sudden infant death syndrome SIDS SUID Infant sleep position risk factors breastfeeding sleep position BACKGROUND Sudden infant death syndrome (SIDS) is the sudden death of an infant under 1 year of age without established cause after thorough investigation, including review of clinical history, circumstances of death, and performance of complete autopsy (1). A recent postmortem surveillance study conducted in Zambia found that 7.4% of infant deaths in the community were due to sudden unexplained infant death (SUID), with nearly 5.4% attributed to apparent SIDS (2). This may indicate a significant incidence of suspected SIDS. However, the prevalence of bed-sharing and prone or side sleeping positions, known risk factors for SIDS, is poorly understood in Zambia due to an apparent lack of research interest. SIDS is a complex phenomenon characterized by multiple interacting risk factors. The triple risk hypothesis suggests that SIDS occurs in infants who have an underlying biological vulnerability and are exposed to an external threat during a critical developmental period. Numerous risk factors for SIDS are well documented globally, including low birth weight, male gender, young maternal age, and multiparity (3). However, research on the prevalence of these non-modifiable risk factors in Zambia is limited to a single cross-sectional survey (4). Additionally, several modifiable factors have been associated with a higher risk of SIDS, such as prone sleeping positions, bedsharing, maternal smoking, and parental alcohol consumption (5). In a recent qualitative study, Osei-Poku et al. (2023) found that mothers viewed the supine sleeping position of their baby as a choking hazard. They also preferred to bedshare with their infants for the convenience of breastfeeding and monitoring the baby (6). Debate persists regarding the potential benefits and risks of shared sleeping practices in relation to SIDS, and there has been little effort to examine the prevalence of these practices in the Zambian context. Moreover, while a myriad of protective factors, including breastfeeding, pacifier use, and immunization, have been associated with SIDS globally (7), no study in Zambia has comprehensively investigated them, partly due to the sluggish uptake and patchy nature of the investigative process surrounding SIDS in Zambia. This research aims to strengthen Osei-Poku’s earlier cross-sectional study by triangulating data from a prospective birth cohort study and a cross-sectional survey, thereby reducing some of the limitations encountered in his earlier work. METHODS Population We investigated infant sleep practices using a structured survey for mothers of 20-week-old infants participating in the Zambian Infant Cohort Study (ZICS). ZICS is a longitudinal observational cohort consisting of 1500 mother-infant dyads in a peri-urban community in Lusaka, Zambia; the methods of ZICS are described elsewhere (8). A structured questionnaire was administered by trained midwives during the 20-week ZICS visit to collect information on the infants' sleeping environment and position from mothers enrolled in the birth cohort. We obtained written informed consent from every participant. For minors, written informed consent was obtained from their parents or guardians. This study was approved by the Institutional Review Boards of Boston University (H-38119) and University Teaching Hospital (Ref: 007-01-19). Analytic method We provide descriptive statistics (median, interquartile range for continuous variables, and frequencies for categorical variables) regarding the demographic characteristics of mothers and infants, as well as the SIDS risk factors related to the sleeping environment. We report the numbers, percentages, and narratives of verbal autopsies linked to SUID. RESULTS Data were collected from 596 caregivers. The majority of the mothers were between the ages of 25 and 34 years (Table 1 a). Most mothers were married, 516/596 (86.6%), and only 6.4% did attain an education beyond secondary school. Alcohol consumption during pregnancy was reported by 12.6% of the women, and smoking was 0.3%. Of the 605 infants included in this study, 50.6% (306/605) were male and 49.4% (299/605) were female (Table 1 b). Additionally, 10.7% (65/605) of respondents had preterm infants (< 37 weeks gestation) confirmed by ultrasound, while 20.2% (122/605) of infants were born with low birth weight, and only one was born with a major abnormality. In our cohort, 43.1% of infants were exclusively breastfed for six months, and 90.2% had some breastfeeding at 6 months. Table 1a: Demographic characteristics of caregivers Question Response Overall How old are you? N 596 Mean (Std Dev) 28 (6) Categorical age 17-24 172 (28.9%) 25-34 319 (53.5%) 35+ 105 (17.6%) 2-category marital status Married 516 (86.6%) Not married 79 (13.3%) No answer 1 (0.2%) What was the highest grade you attended? No formal education 13 (2.2%) Primary 145 (24.3%) Secondary 400 (67.1%) College (and beyond) 38 (6.4%) Do you smoke cigarettes or use other forms of tobacco? No 591 (99.3%) Yes, including during this pregnancy 2 (0.3%) Yes, but stopped in pregnancy 2 (0.3%) Have you drunk any alcohol since you learned you were pregnant? No 520 (87.2%) Yes 75 (12.6%) No answer 1 (0.2%) Table 1b: Demographic characteristics of infants Question Response Overall Total N 605 Sex of baby Male 306 (50.6%) Female 299 (49.4%) Birthweight (categorical) > 2500g 478 (79.0%) LBW (>1500g - 1000g - <=1500g 5 (0.8%) Gestational week Preterm (28 - <34 weeks) 11 (1.8%) Late Preterm (34 < 37 weeks) 54 (8.9%) Term (37 completed weeks) 540 (89.3%) Exclusive breastfeeding through 24 weeks Labor 5 (0.8%) Day 6 16 (2.6%) Week 6 22 (3.6%) Week 10 42 (6.9%) Week 14 105 (17.4%) Week 20 154 (25.5%) Week 24 261 (43.1%) Any breastfeeding through 6 months Labor 5 (0.8%) Day 6 5 (0.8%) Week 6 4 (0.7%) Week 10 4 (0.7%) Week 14 18 (3.0%) Week 20 23 (3.8%) Week 24 546 (90.2%) Major birth anomalies? No 604 (99.8%) Yes 1 (0.2%) Most infants [98.2% (593/605)] shared a sleep surface with other adults, while a smaller number of babies (1.5%) had room sharing without bedsharing (Table 2 ).. Over three-quarters of babies were placed on their sides to sleep [78.5%, (475/605)], and 18% (109/605) of infants were placed in the prone position. A small proportion of infants were placed in the recommended supine or back sleeping position [3.5%, (21/605)]. When asked about the layers of clothing they use to wrap their babies, nearly three-quarters of infants were bundled in two or more layers [74.2%, (447/605)]. Table 2: Risk factors for SIDS Question Response Overall Total N 605 Child age in days at post-natal visit N 605 Mean (Std Dev) 148 (20) Over the last two weeks, in what position have you USUALLY placed your baby to sleep? On the infant’s side (lateral) 475 (78.5%) On the infant’s stomach (prone) 109 (18.0%) On the infant’s back (supine) 21 (3.5%) Where does baby USUALLY sleep? In a parent’s (or other adult’s) room on his/her own mattress or pad 9 (1.5%) In a parent’s (or other adult’s) bed with adult(s) 593 (98.2%) In another child’s room on his/her own mattress or pad 2 (0.3%) Over the last two weeks, what type of outfit did you USUALLY put your baby in for sleeping? Note: Key is to assess how many layers of clothes or bundling is occurring Just a nappy 54 (9.0%) One light layer of clothes 102 (16.9%) Two layers of clothes (for example with romper) 279 (46.3%) Two layers of clothes plus baby tightly swaddled in chitenge 53 (8.8%) Multiple layers including a blanket or shawl 115 (19.1%) Thirty-six infants died during the study period. After careful adjudication of verbal autopsies and clinical case histories, SUID accounted for 8.3% (3/36) of the deceased infants. A complete verbatim account of the narratives from the two mothers whose babies died of SUID is provided below. I woke up to check and turn the baby around 01:00 on Monday (15/08/22) but to my surprise the baby was unresponsive, and blood was seen coming out from the nose and mouth with no pulse. We rushed to the hospital here at Chawama and the baby was declared dead around 02:00. It was shocking. It came so sudden. We didn't see any signs. DISCUSSION The results of this study, which is the first to triangulate SIDS risk factors from both a birth cohort and a cross-sectional study in Zambia, strengthen the findings that both modifiable and non-modifiable risk factors for SIDS are exceptionally prevalent in low socioeconomic settings. We found a SUID prevalence of 8.3%, along with high rates of bedsharing and lateral/prone sleeping positions, which are significant risk factors for SIDS. Our results on infant sleeping positions appear consistent with other research that found a high prevalence of lateral and prone positions. These two positions are reported to carry the highest risk of SIDS among infants. Many mothers, however, believe that the prone and lateral positions prevent infants from accidentally aspirating their vomitus during sleep (6). Our cohort also demonstrated a high uptake of breastfeeding. At six months, 43.1% of infants were reported to have exclusive breastfeeding, while 90.2% reported some form of breastfeeding. The extensive health benefits of breastfeeding for both mothers and infants have been widely reported (12). While breastfeeding is protective against SIDS, it also promotes shared sleeping, as evidenced by the high percentage of infants (98.2%) with reported bedsharing. Most researchers studying SIDS agree on the increased risk associated with bedsharing, particularly in conjunction with prematurity and low birth weight (13). However, others hold differing views. For example, proponents of co-sleeping argue that skin-to-skin contact (kangaroo care), especially among preterm and newborn infants, has empirical benefits. They contend that shared sleeping promotes thermoregulation, maternal-infant bonding, and a longer duration of breastfeeding (14). This contradiction complicates health professionals' ability to offer the best possible advice to mothers. Room sharing without bedsharing is a recognized practice that significantly reduces SIDS. In contrast, only a very small proportion of mothers reported room sharing in our survey. Our findings support previous observations indicating a low prevalence of room sharing without bed sharing in these disadvantaged communities. Several factors could explain this observation. First, many of these families cannot afford a bed for their baby or a larger house due to their socioeconomic circumstances. Second, the culture of breastfeeding might reinforce bedsharing practices instead of room sharing. Although little is known about how much clothing is required to maintain the infant’s thermal comfort, investigators generally agree that hyperthermia from over bundling should be avoided to reduce the risk of SIDS (15). In our study, nearly three-quarters of mothers reported wrapping their babies in two or more layers of clothing. This finding aligns with Osei-Poku’s (2023) results, which indicated that several participants bundled their babies with at least two blankets during sleep. Prematurity and low birth weight are well-known risk factors for SIDS. It has been suggested that the immature autonomic system leaves these infants vulnerable to an increased incidence of SIDS. In our study, a substantial percentage of infants (20.2%) were born with low birth weight. This figure is more than double the percentage of low birth weight recorded in Lusaka in the 2022 annual statistical report (11). This difference can be partly attributed to the higher proportion of HIV-infected mothers in our study sample (data not shown here), who are at an increased risk of delivering a low birth weight or premature baby. This, combined with the high rates of bedsharing, puts these infants at an increased risk of SIDS. It is now well established from a variety of studies that maternal alcohol consumption and smoking increase the risk of SIDS (10). While we found low levels of alcohol consumption and smoking in our cohort of mothers, we cannot draw conclusions about the prevalence of maternal smoking and alcohol consumption among SIDS mothers due to the scarcity of prospectively obtained SIDS incidences. A significant number of mothers in our study did not attain an education level beyond secondary school. This finding was also reported by Osei-Poku et al. (2022). Given that most SIDS prevention campaigns focus on parental education and behavioral modification of infant care, this finding is noteworthy. Educational campaigns for SIDS in Zambia should be customized for mothers with low literacy (9). Limitations It is a limitation of our study that we had to rely on self-reported data, particularly regarding risk factors associated with infant care practices. However, significant strengths of the study include the triangulation of data from the prospective cohort. For instance, we were able to obtain precise birth weight and gestational age by utilizing accurate dating through ultrasound. Furthermore, we gathered more accurate breastfeeding patterns by administering a questionnaire during several routine visits. CONCLUSION This study set out to investigate the risk and protective factors of SIDS in a low socio-economic setting. Our research confirms what others have found recently: that infant sleep and environment-related risk factors for SIDS are highly prevalent in disadvantaged communities. We also noted an increasing number of low birthweight and preterm infants who face a greater risk of SIDS in these vulnerable communities. Future public health promotion will need to address these challenges through carefully designed and targeted education for parents, grandparents, and healthcare providers. What is now needed is a cross-national study involving both rural and urban areas. Indeed, our ongoing study on SIDS (Project Chisoni) already seeks to move beyond observational associations and toward stronger evidence that address issues of categorization and causality. Abbreviations SIDS Sudden Infant Death Syndrome SUID Sudden Unexpected Infant Death MoH Ministry of Health HIV Human Immune Virus Declarations ACKNOWLEDGMENTS We would like to acknowledge the hard work and dedication of our data collection team: Charles Nthele, Florence Mulenga, Clara Ngwenya, Chola Sampa Chipendano, Victoria Chalikosa, Victor Mwika Chanda, and Carol Buumba Masempela. Most importantly, we are forever indebted to the women and children who shared their lives with our team. Thank you for your trust. AUTHORS’ CONTRIBUTIONS JH, BPL, DMT helped conceptualize the study. LF, JS and TH performed the data analysis. EZ wrote the original draft. JH, CD, GOP, LM, RC, SS, RP and CG reviewed the manuscript. DATA AVAILABILITY Data that support the results of this study is available on BEDAC repository and can be shared upon request. Ethics approval and consent to participate The study was approved by both the University of Zambia Biomedical Research Ethics Committee (Ref: 007-01-19) and Boston University Institutional Review Board (H-38119). Written informed consent was obtained from every participant. For minors, written informed consent was obtained from their parents or guardians. Funding The birth cohort was funded by NIH/National Institute of Child Health and Humam Development (NICHD) (NIH-NICHD) Trial number: 1R01HD094650 References Willinger M, James LC, Catz C. Defining the Sudden Infant Death Syndrome (Sids): Deliberations of an Expert Panel Convened by the National Institute of Child Health and Human Development. Pediatric pathology. 1991; 11(5): 677-684. Available from: https://doi.org/10.3109/15513819109065465 Osei-Poku GK, Mwananyanda L, Elliot PA. The apparent burden of unexplained sudden infant deaths in Lusaka, Zambia: Findings from analysis of verbal autopsies. Gates Open Research. 2023; 7(46). Available from: https://doi.org/10.12688/gatesopenres.14303.1 Duncan JR, Byard RW. SIDS Sudden Infant and Early Childhood Death: The Past, the Present and the Future Adelaide (AU: University of Adelaide Press; 2018. Osei-Poku GK, Mwananyanda L, Elliot PA, MacLeod WB, Somwe SW, Pieciak RC et al. Assessing infant sleep practices and other risk factors of SIDS in Zambia: a cross-sectional survey of mothers in Lusaka, Zambia. BMC pediatrics. 2022; 22(1): 660. Available from: https://doi.org/10.1186/s12887-022-03712-5 Mitchell EA, Thompson JM, Zuccollo J, MacFarlane M, Taylor B, Elder D et al. The combination of bed sharing and maternal smoking leads to a greatly increased risk of sudden unexpected death in infancy: the New Zealand SUDI Nationwide Case Control Study. The New Zealand medical journal. 2017 June 2; 130(1456): 52-64. Osei-Poku GK, Mwananyanda L, Elliott PA, MacLeod WB, Somwe SW, Pieciak RC et al. Qualitative assessment of infant sleep practices and other risk factors of sudden infant death syndrome (SIDS) among mothers in Lusaka, Zambia. BMC pediatrics. 2023; 23(1): 245. Available from: https://doi.org/10.1186/s12887-023-04051-9  Mitchell EA, Krous HF. Sudden unexpected death in infancy: a historical perspective. Journal of paediatrics and child health. 2015; 51(1): 108-112. Available from: https://doi.org/10.1111/jpc.12818 Duffy CR, Herlihy JM, Zulu E, Mwananyanda L, Forman L, Heeren T et al. Preterm birth among women with HIV: impact of preconception cART initiation. AIDS. 2024; 38(12): 1749-1757. Available from: https://doi.org/10.1097/QAD.0000000000003979 Yamada MM, Rosamilia MB, Chiswell KE, D'Ottavio A, Spears T, Osgood C et al. Risk Factors for Sudden Infant Death in North Carolina. Frontiers in pediatrics. 2021; 9: 770803. Available from: https://doi.org/10.3389/fped.2021.770803 Hauck FR, Blackstone SR. Maternal Smoking, Alcohol and Recreational Drug Use and the Risk of SIDS Among a US Urban Black Population. Frontiers in pediatrics. 2022; 10: 809966. Available from: https://doi.org/10.3389/fped.2022.809966 Ministry of Health. Annual heath statistical report. Lusaka: 2022. Available from: https://www.moh.gov.zm/?wpfb_dl=231 Sharp M, Campbell C, Chiffings D, Simmer K, French N. Improvement in long-term breastfeeding for very preterm infants. Breastfeeding medicine. the official journal of the Academy of Breastfeeding Medicine. 2015; 10(3): 145-149. Available from: https://doi.org/10.1089/bfm.2014.0117 Matthijsse PR, Semmekrot BA, Liem KD. Skin to skin contact and breast-feeding after birth: not always without risk! Nederlands tijdschrift voor geneeskunde. 2016; 160. Mekonnen AG, Yehualashet SS, Bayleyegn AD. The effects of kangaroo mother care on the time to breastfeeding initiation among preterm and LBW infants: a meta-analysis of published studies. International breastfeeding journal. 2019; 14: 12. Available from: https://doi.org/10.1186/s13006-019-0206-0 Bach V, Libert JP. Hyperthermia and Heat Stress as Risk Factors for Sudden Infant Death Syndrome: A Narrative Review. Frontiers in pediatrics. 2022; 10: 816136. Available from: https://doi.org/10.3389/fped.2022.816136 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6427293","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":454370730,"identity":"788dc048-7d34-4bfa-91cb-9de80bc2ce44","order_by":0,"name":"Ethan M. 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A recent postmortem surveillance study conducted in Zambia found that 7.4% of infant deaths in the community were due to sudden unexplained infant death (SUID), with nearly 5.4% attributed to apparent SIDS (2). This may indicate a significant incidence of suspected SIDS. However, the prevalence of bed-sharing and prone or side sleeping positions, known risk factors for SIDS, is poorly understood in Zambia due to an apparent lack of research interest.\u003c/p\u003e \u003cp\u003eSIDS is a complex phenomenon characterized by multiple interacting risk factors. The triple risk hypothesis suggests that SIDS occurs in infants who have an underlying biological vulnerability and are exposed to an external threat during a critical developmental period. Numerous risk factors for SIDS are well documented globally, including low birth weight, male gender, young maternal age, and multiparity (3). However, research on the prevalence of these non-modifiable risk factors in Zambia is limited to a single cross-sectional survey (4). Additionally, several modifiable factors have been associated with a higher risk of SIDS, such as prone sleeping positions, bedsharing, maternal smoking, and parental alcohol consumption (5). In a recent qualitative study, Osei-Poku et al. (2023) found that mothers viewed the supine sleeping position of their baby as a choking hazard. They also preferred to bedshare with their infants for the convenience of breastfeeding and monitoring the baby (6). Debate persists regarding the potential benefits and risks of shared sleeping practices in relation to SIDS, and there has been little effort to examine the prevalence of these practices in the Zambian context.\u003c/p\u003e \u003cp\u003eMoreover, while a myriad of protective factors, including breastfeeding, pacifier use, and immunization, have been associated with SIDS globally (7), no study in Zambia has comprehensively investigated them, partly due to the sluggish uptake and patchy nature of the investigative process surrounding SIDS in Zambia. This research aims to strengthen Osei-Poku\u0026rsquo;s earlier cross-sectional study by triangulating data from a prospective birth cohort study and a cross-sectional survey, thereby reducing some of the limitations encountered in his earlier work.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePopulation\u003c/h2\u003e \u003cp\u003eWe investigated infant sleep practices using a structured survey for mothers of 20-week-old infants participating in the Zambian Infant Cohort Study (ZICS). ZICS is a longitudinal observational cohort consisting of 1500 mother-infant dyads in a peri-urban community in Lusaka, Zambia; the methods of ZICS are described elsewhere (8). A structured questionnaire was administered by trained midwives during the 20-week ZICS visit to collect information on the infants' sleeping environment and position from mothers enrolled in the birth cohort. We obtained written informed consent from every participant. For minors, written informed consent was obtained from their parents or guardians. This study was approved by the Institutional Review Boards of Boston University (H-38119) and University Teaching Hospital (Ref: 007-01-19).\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eAnalytic method\u003c/h3\u003e\n\u003cp\u003eWe provide descriptive statistics (median, interquartile range for continuous variables, and frequencies for categorical variables) regarding the demographic characteristics of mothers and infants, as well as the SIDS risk factors related to the sleeping environment. We report the numbers, percentages, and narratives of verbal autopsies linked to SUID.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eData were collected from 596 caregivers. The majority of the mothers were between the ages of 25 and 34 years (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). Most mothers were married, 516/596 (86.6%), and only 6.4% did attain an education beyond secondary school. Alcohol consumption during pregnancy was reported by 12.6% of the women, and smoking was 0.3%. Of the 605 infants included in this study, 50.6% (306/605) were male and 49.4% (299/605) were female (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). Additionally, 10.7% (65/605) of respondents had preterm infants (\u0026lt;\u0026thinsp;37 weeks gestation) confirmed by ultrasound, while 20.2% (122/605) of infants were born with low birth weight, and only one was born with a major abnormality. In our cohort, 43.1% of infants were exclusively breastfed for six months, and 90.2% had some breastfeeding at 6 months.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 1a: Demographic characteristics of caregivers\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"654\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 306px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eQuestion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eResponse\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOverall\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 306px;\"\u003e\n \u003cp\u003eHow old are you?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eN\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e596\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eMean (Std Dev)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e28 (6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 306px;\"\u003e\n \u003cp\u003eCategorical age\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003e17-24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e172 (28.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003e25-34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e319 (53.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003e35+\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e105 (17.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 306px;\"\u003e\n \u003cp\u003e2-category marital status\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eMarried\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e516 (86.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eNot married\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e79 (13.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eNo answer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e1 (0.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" style=\"width: 306px;\"\u003e\n \u003cp\u003eWhat was the highest grade you attended?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eNo formal education\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e13 (2.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003ePrimary\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e145 (24.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eSecondary\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e400 (67.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eCollege (and beyond)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e38 (6.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 306px;\"\u003e\n \u003cp\u003eDo you smoke cigarettes or use other forms of tobacco?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e591 (99.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eYes, including during this pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e2 (0.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eYes, but stopped in pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e2 (0.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 306px;\"\u003e\n \u003cp\u003eHave you drunk any alcohol since you learned you were pregnant?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e520 (87.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e75 (12.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 228px;\"\u003e\n \u003cp\u003eNo answer\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e1 (0.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 1b: Demographic characteristics of infants\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" class=\"fr-table-selection-hover\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 247px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eQuestion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eResponse\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOverall\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 247px;\"\u003e\n \u003cp\u003eTotal N\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e605\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 247px;\"\u003e\n \u003cp\u003eSex of baby\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e306 (50.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e299 (49.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 247px;\"\u003e\n \u003cp\u003eBirthweight (categorical)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003e\u0026gt; 2500g\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e478 (79.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eLBW (\u0026gt;1500g - \u0026lt;=2500g\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e122 (20.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eVLBW (\u0026gt;1000g - \u0026lt;=1500g\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e5 (0.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 247px;\"\u003e\n \u003cp\u003eGestational week\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003ePreterm (28 - \u0026lt;34 weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e11 (1.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eLate Preterm (34 \u0026lt; 37 weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e54 (8.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eTerm (37 completed weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e540 (89.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"7\" style=\"width: 247px;\"\u003e\n \u003cp\u003eExclusive breastfeeding through 24 weeks\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eLabor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e5 (0.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eDay 6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e16 (2.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e22 (3.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e42 (6.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e105 (17.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e154 (25.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e261 (43.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"7\" style=\"width: 247px;\"\u003e\n \u003cp\u003eAny breastfeeding through 6 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eLabor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e5 (0.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eDay 6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e5 (0.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e4 (0.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e4 (0.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e18 (3.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e23 (3.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eWeek 24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e546 (90.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 247px;\"\u003e\n \u003cp\u003eMajor birth anomalies?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e604 (99.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 192px;\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 91px;\"\u003e\n \u003cp\u003e1 (0.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\u003cp\u003eMost infants [98.2% (593/605)] shared a sleep surface with other adults, while a smaller number of babies (1.5%) had room sharing without bedsharing (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).. Over three-quarters of babies were placed on their sides to sleep [78.5%, (475/605)], and 18% (109/605) of infants were placed in the prone position. A small proportion of infants were placed in the recommended supine or back sleeping position [3.5%, (21/605)]. When asked about the layers of clothing they use to wrap their babies, nearly three-quarters of infants were bundled in two or more layers [74.2%, (447/605)].\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e\u003cem\u003eTable 2: Risk factors for SIDS\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"723\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 275px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eQuestion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eResponse\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOverall\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 275px;\"\u003e\n \u003cp\u003eTotal N\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e605\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 275px;\"\u003e\n \u003cp\u003eChild age in days at post-natal visit\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eN\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e605\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eMean (Std Dev)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e148 (20)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 275px;\"\u003e\n \u003cp\u003eOver the last two weeks, in what position have you USUALLY placed your baby to sleep?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eOn the infant\u0026rsquo;s side (lateral)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e475 (78.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eOn the infant\u0026rsquo;s stomach (prone)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e109 (18.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eOn the infant\u0026rsquo;s back (supine)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e21 (3.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 275px;\"\u003e\n \u003cp\u003eWhere does baby USUALLY sleep?\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eIn a parent\u0026rsquo;s (or other adult\u0026rsquo;s) room on his/her own mattress or pad\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e9 (1.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eIn a parent\u0026rsquo;s (or other adult\u0026rsquo;s) bed with adult(s)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e593 (98.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eIn another child\u0026rsquo;s room on his/her own mattress or pad\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e2 (0.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"5\" style=\"width: 275px;\"\u003e\n \u003cp\u003eOver the last two weeks, what type of outfit did you USUALLY put your baby in for sleeping? Note: Key is to assess how many layers of clothes or bundling is occurring\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eJust a nappy\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e54 (9.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eOne light layer of clothes\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e102 (16.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eTwo layers of clothes (for example with romper)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e279 (46.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eTwo layers of clothes plus baby tightly swaddled in chitenge\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e53 (8.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 285px;\"\u003e\n \u003cp\u003eMultiple layers including a blanket or shawl\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e115 (19.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\u003cp\u003eThirty-six infants died during the study period. After careful adjudication of verbal autopsies and clinical case histories, SUID accounted for 8.3% (3/36) of the deceased infants. A complete verbatim account of the narratives from the two mothers whose babies died of SUID is provided below.\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003eI woke up to check and turn the baby around 01:00 on Monday (15/08/22) but to my surprise the baby was unresponsive, and blood was seen coming out from the nose and mouth with no pulse. We rushed to the hospital here at Chawama and the baby was declared dead around 02:00.\u003c/p\u003e\u003cp\u003eIt was shocking. It came so sudden. We didn't see any signs.\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThe results of this study, which is the first to triangulate SIDS risk factors from both a birth cohort and a cross-sectional study in Zambia, strengthen the findings that both modifiable and non-modifiable risk factors for SIDS are exceptionally prevalent in low socioeconomic settings. We found a SUID prevalence of 8.3%, along with high rates of bedsharing and lateral/prone sleeping positions, which are significant risk factors for SIDS.\u003c/p\u003e \u003cp\u003eOur results on infant sleeping positions appear consistent with other research that found a high prevalence of lateral and prone positions. These two positions are reported to carry the highest risk of SIDS among infants. Many mothers, however, believe that the prone and lateral positions prevent infants from accidentally aspirating their vomitus during sleep (6). Our cohort also demonstrated a high uptake of breastfeeding. At six months, 43.1% of infants were reported to have exclusive breastfeeding, while 90.2% reported some form of breastfeeding. The extensive health benefits of breastfeeding for both mothers and infants have been widely reported (12). While breastfeeding is protective against SIDS, it also promotes shared sleeping, as evidenced by the high percentage of infants (98.2%) with reported bedsharing. Most researchers studying SIDS agree on the increased risk associated with bedsharing, particularly in conjunction with prematurity and low birth weight (13). However, others hold differing views. For example, proponents of co-sleeping argue that skin-to-skin contact (kangaroo care), especially among preterm and newborn infants, has empirical benefits. They contend that shared sleeping promotes thermoregulation, maternal-infant bonding, and a longer duration of breastfeeding (14). This contradiction complicates health professionals' ability to offer the best possible advice to mothers.\u003c/p\u003e \u003cp\u003eRoom sharing without bedsharing is a recognized practice that significantly reduces SIDS. In contrast, only a very small proportion of mothers reported room sharing in our survey. Our findings support previous observations indicating a low prevalence of room sharing without bed sharing in these disadvantaged communities. Several factors could explain this observation. First, many of these families cannot afford a bed for their baby or a larger house due to their socioeconomic circumstances. Second, the culture of breastfeeding might reinforce bedsharing practices instead of room sharing. Although little is known about how much clothing is required to maintain the infant\u0026rsquo;s thermal comfort, investigators generally agree that hyperthermia from over bundling should be avoided to reduce the risk of SIDS (15). In our study, nearly three-quarters of mothers reported wrapping their babies in two or more layers of clothing. This finding aligns with Osei-Poku\u0026rsquo;s (2023) results, which indicated that several participants bundled their babies with at least two blankets during sleep.\u003c/p\u003e \u003cp\u003ePrematurity and low birth weight are well-known risk factors for SIDS. It has been suggested that the immature autonomic system leaves these infants vulnerable to an increased incidence of SIDS. In our study, a substantial percentage of infants (20.2%) were born with low birth weight. This figure is more than double the percentage of low birth weight recorded in Lusaka in the 2022 annual statistical report (11). This difference can be partly attributed to the higher proportion of HIV-infected mothers in our study sample (data not shown here), who are at an increased risk of delivering a low birth weight or premature baby. This, combined with the high rates of bedsharing, puts these infants at an increased risk of SIDS.\u003c/p\u003e \u003cp\u003eIt is now well established from a variety of studies that maternal alcohol consumption and smoking increase the risk of SIDS (10). While we found low levels of alcohol consumption and smoking in our cohort of mothers, we cannot draw conclusions about the prevalence of maternal smoking and alcohol consumption among SIDS mothers due to the scarcity of prospectively obtained SIDS incidences. A significant number of mothers in our study did not attain an education level beyond secondary school. This finding was also reported by Osei-Poku et al. (2022). Given that most SIDS prevention campaigns focus on parental education and behavioral modification of infant care, this finding is noteworthy. Educational campaigns for SIDS in Zambia should be customized for mothers with low literacy (9).\u003c/p\u003e\n\u003ch3\u003eLimitations\u003c/h3\u003e\n\u003cp\u003eIt is a limitation of our study that we had to rely on self-reported data, particularly regarding risk factors associated with infant care practices. However, significant strengths of the study include the triangulation of data from the prospective cohort. For instance, we were able to obtain precise birth weight and gestational age by utilizing accurate dating through ultrasound. Furthermore, we gathered more accurate breastfeeding patterns by administering a questionnaire during several routine visits.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eThis study set out to investigate the risk and protective factors of SIDS in a low socio-economic setting. Our research confirms what others have found recently: that infant sleep and environment-related risk factors for SIDS are highly prevalent in disadvantaged communities. We also noted an increasing number of low birthweight and preterm infants who face a greater risk of SIDS in these vulnerable communities. Future public health promotion will need to address these challenges through carefully designed and targeted education for parents, grandparents, and healthcare providers. What is now needed is a cross-national study involving both rural and urban areas. Indeed, our ongoing study on SIDS (Project Chisoni) already seeks to move beyond observational associations and toward stronger evidence that address issues of categorization and causality.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eSIDS \u0026nbsp; \u0026nbsp; Sudden Infant Death Syndrome\u003c/p\u003e\n\u003cp\u003eSUID \u0026nbsp; \u0026nbsp;Sudden Unexpected Infant Death\u003c/p\u003e\n\u003cp\u003eMoH \u0026nbsp; \u0026nbsp;Ministry of Health\u003c/p\u003e\n\u003cp\u003eHIV \u0026nbsp; \u0026nbsp; \u0026nbsp;Human Immune Virus\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eACKNOWLEDGMENTS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to acknowledge the hard work and dedication of our data collection team: Charles Nthele, Florence Mulenga, Clara Ngwenya, Chola Sampa Chipendano, Victoria Chalikosa, Victor Mwika Chanda, and Carol Buumba Masempela. Most importantly, we are forever indebted to the women and children who shared their lives with our team. Thank you for your trust.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAUTHORS\u0026rsquo; CONTRIBUTIONS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJH, BPL, DMT helped conceptualize the study. LF, JS and TH performed the data analysis. EZ wrote the original draft. JH, CD, GOP, LM, RC, SS, RP and CG reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDATA AVAILABILITY\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData that support the results of this study is available on BEDAC repository and can be shared upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was approved by both the University of Zambia Biomedical Research Ethics Committee (Ref: 007-01-19) and Boston University Institutional Review Board (H-38119). Written informed consent was obtained from every participant. For minors, written informed consent was obtained from their parents or guardians.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe birth cohort was funded by NIH/National Institute of Child Health and Humam Development (NICHD) (NIH-NICHD) Trial number: 1R01HD094650\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eWillinger M, James LC, Catz C. Defining the Sudden Infant Death Syndrome (Sids): Deliberations of an Expert Panel Convened by the National Institute of Child Health and Human Development. Pediatric pathology. 1991; 11(5): 677-684. Available from: https://doi.org/10.3109/15513819109065465\u003c/li\u003e\n\u003cli\u003eOsei-Poku GK, Mwananyanda L, Elliot PA. The apparent burden of unexplained sudden infant deaths in Lusaka, Zambia: Findings from analysis of verbal autopsies. Gates Open Research. 2023; 7(46). Available from: https://doi.org/10.12688/gatesopenres.14303.1\u003c/li\u003e\n\u003cli\u003eDuncan JR, Byard RW. SIDS Sudden Infant and Early Childhood Death: The Past, the Present and the Future Adelaide (AU: University of Adelaide Press; 2018. \u003c/li\u003e\n\u003cli\u003eOsei-Poku GK, Mwananyanda L, Elliot PA, MacLeod WB, Somwe SW, Pieciak RC et al. Assessing infant sleep practices and other risk factors of SIDS in Zambia: a cross-sectional survey of mothers in Lusaka, Zambia. BMC pediatrics. 2022; 22(1): 660. Available from: https://doi.org/10.1186/s12887-022-03712-5\u003c/li\u003e\n\u003cli\u003eMitchell EA, Thompson JM, Zuccollo J, MacFarlane M, Taylor B, Elder D et al. The combination of bed sharing and maternal smoking leads to a greatly increased risk of sudden unexpected death in infancy: the New Zealand SUDI Nationwide Case Control Study. The New Zealand medical journal. 2017 June 2; 130(1456): 52-64. \u003c/li\u003e\n\u003cli\u003eOsei-Poku GK, Mwananyanda L, Elliott PA, MacLeod WB, Somwe SW, Pieciak RC et al. Qualitative assessment of infant sleep practices and other risk factors of sudden infant death syndrome (SIDS) among mothers in Lusaka, Zambia. BMC pediatrics. 2023; 23(1): 245. Available from: https://doi.org/10.1186/s12887-023-04051-9\u0026amp;nbsp;\u003c/li\u003e\n\u003cli\u003eMitchell EA, Krous HF. Sudden unexpected death in infancy: a historical perspective. Journal of paediatrics and child health. 2015; 51(1): 108-112. Available from: https://doi.org/10.1111/jpc.12818\u003c/li\u003e\n\u003cli\u003eDuffy CR, Herlihy JM, Zulu E, Mwananyanda L, Forman L, Heeren T et al. Preterm birth among women with HIV: impact of preconception cART initiation. AIDS. 2024; 38(12): 1749-1757. Available from: https://doi.org/10.1097/QAD.0000000000003979\u003c/li\u003e\n\u003cli\u003eYamada MM, Rosamilia MB, Chiswell KE, D\u0026apos;Ottavio A, Spears T, Osgood C et al. Risk Factors for Sudden Infant Death in North Carolina. Frontiers in pediatrics. 2021; 9: 770803. Available from: https://doi.org/10.3389/fped.2021.770803\u003c/li\u003e\n\u003cli\u003eHauck FR, Blackstone SR. Maternal Smoking, Alcohol and Recreational Drug Use and the Risk of SIDS Among a US Urban Black Population. Frontiers in pediatrics. 2022; 10: 809966. Available from: https://doi.org/10.3389/fped.2022.809966\u003c/li\u003e\n\u003cli\u003eMinistry of Health. Annual heath statistical report. Lusaka: 2022. Available from: https://www.moh.gov.zm/?wpfb_dl=231\u003c/li\u003e\n\u003cli\u003eSharp M, Campbell C, Chiffings D, Simmer K, French N. Improvement in long-term breastfeeding for very preterm infants. Breastfeeding medicine. the official journal of the Academy of Breastfeeding Medicine. 2015; 10(3): 145-149. Available from: https://doi.org/10.1089/bfm.2014.0117\u003c/li\u003e\n\u003cli\u003eMatthijsse PR, Semmekrot BA, Liem KD. Skin to skin contact and breast-feeding after birth: not always without risk! Nederlands tijdschrift voor geneeskunde. 2016; 160.\u003c/li\u003e\n\u003cli\u003eMekonnen AG, Yehualashet SS, Bayleyegn AD. The effects of kangaroo mother care on the time to breastfeeding initiation among preterm and LBW infants: a meta-analysis of published studies. International breastfeeding journal. 2019; 14: 12. Available from: https://doi.org/10.1186/s13006-019-0206-0\u003c/li\u003e\n\u003cli\u003eBach V, Libert JP. Hyperthermia and Heat Stress as Risk Factors for Sudden Infant Death Syndrome: A Narrative Review. Frontiers in pediatrics. 2022; 10: 816136. Available from: https://doi.org/10.3389/fped.2022.816136\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Sudden infant death syndrome, SIDS, SUID, Infant sleep position, risk factors, breastfeeding, sleep position","lastPublishedDoi":"10.21203/rs.3.rs-6427293/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6427293/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDespite a reduction in Sudden Unexplained Infant Death (SUID) in high-income countries, the incidence of SUID and the prevalence of its risk and protective factors remain poorly understood in Zambia due to limited research. The aim of our study was to describe the infant sleep positions and sleep environments in an urban Zambian population to gain a better understanding of the modifiable risk factors for SUID.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData from the Zambian Infant Cohort Study (ZICS), a prospective birth cohort, were collected to describe infant sleep practices in Chawama, a densely populated peri-urban community in Lusaka, Zambia. During the 20-week study visit a structured questionnaire was administered to obtain data about the sleeping and environmental risks associated with SUID.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData were collected from 596 caregivers and 605 infants. Only 6.4% of caregivers did attain an education beyond secondary school, and a significant proportion of infants (20.2%) had low birth weights, with 10.7% of infants confirmed by ultrasound as preterm. Furthermore, 96.5% of infants were placed to sleep on their side or in a prone position, and 98.2% of infants shared a sleep surface with their caregiver. Breastfeeding, a protective factor, was highly prevalent, with 90.2% of infants receiving some form of breastfeeding at the 24-week visit.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe results of this study show that both modifiable (bed-sharing and prone sleep position) and non-modifiable risk factors (low birthweight and prematurity) of SUID are prevalent in this low socioeconomic setting in Zambia. Public health strategies to prevent SUID will need to be innovative and culturally congruent in addressing modifiable risks, such as bedsharing, in settings where there is a lack of space.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration: \u003c/strong\u003eTrial number: 1R01HD094650\u003c/p\u003e","manuscriptTitle":"Present or Absent: Risks and protective factors of sudden infant death syndrome (SIDS) in the Zambian context","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-13 12:15:23","doi":"10.21203/rs.3.rs-6427293/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6472240b-0757-422b-8790-54476244a738","owner":[],"postedDate":"May 13th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-15T10:17:52+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-13 12:15:23","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6427293","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6427293","identity":"rs-6427293","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}