The American Academy of Pediatrics (AAP) issued recommendations in 2005 and 2011 to reduce sleep-related infant death, which advise against all bedsharing for sleep. These recommendations overemphasize the risks of bedsharing, and this overemphasis has serious unintended consequences. It may result in increased deaths on sofas as tired parents try to avoid feeding their infants in bed. Current evidence shows that other risks are far more potent, such as smoking, shared sleep on sofas, sleeping next to impaired caregivers, and formula feeding.
Volume 9, Number 9, 2014
ª Mary Ann Liebert, Inc.
Speaking Out on Safe Sleep: Evidence-Based Infant Sleep Recommendations
To cite this article:
Bartick Melissa and Smith Linda J.. Breastfeeding Medicine. November 2014, 9(9): 417-422. doi:10.1089/bfm.2014.0113.
Published in Volume: 9 Issue 9: October 31, 2014
Online Ahead of Print: September 4, 2014
Melissa Bartick1 and Linda J. Smith2
1Department of Medicine, Cambridge Health Alliance and Harvard Medical School, Cambridge, Massachusetts.
2Center for Global Health, Boonshoft School of Medicine, Wright State University, Dayton, Ohio.
Address correspondence to:
Melissa Bartick, MD, MSc; Department of Medicine; Cambridge Health Alliance and Harvard Medical School; 1493 Cambridge Street; Cambridge, MA 02139
The American Academy of Pediatrics (AAP) issued recommendations in 2005 and 2011 to reduce sleep-related infant death, which advise against all bedsharing for sleep. These recommendations overemphasize the risks of bedsharing, and this overemphasis has serious unintended consequences. It may result in increased deaths on sofas as tired parents try to avoid feeding their infants in bed. Current evidence shows that other risks are far more potent, such as smoking, shared sleep on sofas, sleeping next to impaired caregivers, and formula feeding. The emphasis on separate sleep is diverting resources away from addressing these critical risk factors. Recommendations to avoid bedsharing may also interfere with breastfeeding. We examine both the evidence behind the AAP recommendations and the evidence omitted from those recommendations. We conclude that the only evidence-based universal advice to date is that sofas are hazardous places for adults to sleep with infants; that exposure to smoke, both prenatal and postnatal, increases the risk of death; and that sleeping next to an impaired caregiver increases the risk of death. No sleep environment is completely safe. Public health efforts must address the reality that tired parents must feed their infants at night somewhere and that sofas are highly risky places for parents to fall asleep with their infants, especially if parents are smokers or under the influence of alcohol or drugs. All messaging must be crafted and reevaluated to avoid unintended negative consequences, including impact on breastfeeding rates, or falling asleep in more dangerous situations than parental beds. We must realign our resources to focus on the greater risk factors, and that may include greater investment in smoking cessation and doing away with aggressive formula marketing. This includes eliminating conflicts of interest between formula marketing companies and organizations dedicated to the health of children.
Reducing sleep-related infant deaths is a national priority, but the current recommendations overemphasize the risks of bedsharing and can have serious unintended consequences. The advice never to bedshare may result in deaths on sofas as parents try to avoid feeding their infants in bed. The emphasis on avoiding bedsharing is also diverting valuable resources away from addressing more potent risks for sleep-related infant death. Finally, recommendations to avoid bedsharing may interfere with breastfeeding,1,2 which has wide-ranging public health implications.
The American Academy of Pediatrics (AAP) issued recommendations in 2005 and 2011 to prevent sleep-related infant death, which advises that against all bedsharing for sleep.3,4 This advice has resulted in a proliferation of high-profile local and national initiatives against bedsharing, including frightening ads with headstones and caskets and costly programs to provide free cribs to poor families.
Annually in the United States, there are about 4,000 infant deaths per year related to sleep, 2,200 (55%) of which are due to sudden infant death syndrome (SIDS), with the rest being due to accidental suffocation or strangulation related to sleep, often when a parent or other adult falls asleep next to an infant. These two types of death are distinct entities, with separate but overlapping risk factors, and the AAP recommendation is intended to address both. The leading modifiable risk factors for SIDS are smoking,5 the baby sleeping prone,5 formula feeding,6 the baby sleeping unattended,5 and poverty.7,8 Sofas and soft sleep surfaces have been reported.9 The leading modifiable risk factors for suffocation and smothering are sofa-sleeping9 and parental use of alcohol and drugs.9 In Table 1, we have included Class A recommendations that we think the evidence clearly and strongly supports.
Table 1. Class A Recommendations to Reduce the Risk of SIDS
Class A recommendations to reduce the risk of SIDS, in order of evidence
Class A evidence to reduce the risk of SASS, in order, for at least the first 4–6 months
1. Back to sleep for every sleep.17,49
1. Avoid feeding infants on sofas or recliners when the adult is likely to fall asleep during feeding. This applies to all caregivers, including breastfeeding mothers. (Most accidental smothering/entrapment infant deaths involve sofas or recliners.) 3,9,10,14
SASS, sleep-associated suffocation and strangulation; SIDS, sudden infant death syndrome; WHO, World Health Organization.
Evidence suggests the AAP's recommendation about bedsharing may be counterproductive, directly contributing to infant deaths in at least some cases. A 2010 survey of nearly 5,000 U.S. mothers found “in a possible attempt to avoid bed sharing, 55 percent of mothers feed their babies at night on chairs, recliners or sofas. Forty-four percent (25 percent of the sample) admit that they [are] falling asleep with their babies in these locations.”10 This is cause for alarm and should have triggered immediate re-evaluation of the AAP 2005 recommendation and further study, but instead the recommendation was reiterated in its 2011 statement.
Experts agree that sofas pose a much higher risk for infant death than beds.3,9 Parents of two SIDS deaths described exactly this scenario, unaware that sofas are far more dangerous places for infants to sleep than beds.9 In the United Kingdom, deaths from SIDS have been falling since the early 1990s, but deaths on sofas have nearly tripled since 1996.9 In the United States, deaths from SIDS has been falling while deaths from accidental suffocation and strangulation in bed (ASSB) has more than tripled between 1996 and 2004, with just over a quarter of those documented to have occurred in a bed.11 Of concern is the observation in the United Kingdom that “that smokers may sofa share is not surprising given that they are specifically advised not to bedshare.”12
A large problem in the literature is that many studies continue to define “bedsharing” as any shared sleep surface, even though it has been increasingly clear that some sleep surfaces, such as sofas, are markedly more risky than others. To make matters worse, the term used in the literature, “accidental suffocation and strangulation in bed,” includes deaths related to sleep in any sleep location, including sofas and recliners. We therefore propose eliminating “ASSB” and replacing it with “SASS” (sleep-associated suffocation and strangulation) because a significant proportion of these deaths actually occur on surfaces that have been documented to be highly unsafe for infant sleep: sofas and recliners.
Indeed, the bulk of the literature indicates that sleeping in a parental bed poses little excess risk, absent other risk factors (smoking, formula feeding, prone position, and alcohol/drug use),1,9,12–14 especially if done routinely.15 For example, in an Alaskan study, 94% of infant deaths with bedsharing from SIDS or SASS had at least one of five other risk factors, with maternal smoking being by far the most common (75%).14
An emerging consideration is whether bedsharing is planned and routine or accidental and unintentional. Some data show that infants of parents who bedshare intentionally carry no excess risk, when other known risks are absent.15 More research is needed, but this result is not unexpected if parents are educated about safety issues and plan accordingly. A 2013 article pooling five studies looked closely at bedsharing (as narrowly defined), feeding method, smoking, and drug/alcohol use and found that bedsharing is still a significant risk in unimpaired nonsmoking breastfeeding parents, but only in infants under 15 weeks of age.16 Although they did use a control group, they did not examine routine versus unplanned bedsharing and did not collect data on partner's alcohol use, prenatal smoking (only postnatal), or prematurity.
Nonetheless, other studies continue to be published and reported in the mainstream media that buttress the AAP recommendations, which have overly broad definitions of “bedsharing” or do not account for other risk factors. A 2012 meta-analysis included sofa deaths in the bedsharing definition, but nonetheless concluded that infants who bedshared routinely were not at increased risk of SIDS.15 A 2009 German study on sleep environment and a 2003 U.S. study both showed that a significant number of SIDS deaths occurred in the parental bed but collected no data on parental alcohol use, drug use, or smoking, yet nonetheless concluded by supporting the same position as the AAP on bedsharing.17,18 A similarly designed U.S. study was published in 2014, with the same conclusions.19
Increasing evidence shows that one of the strongest risk factors for SIDS is infant formula feeding.6,20 Formula-fed infants are less arousable than breastfed infants6 and wake less often for feedings. The best, most recently conducted meta-analysis of SIDS cases showed that in the month before death, the odds of SIDS was 27% among exclusively breastfed infants compared with formula-fed infants and 29% among infants who were mixed-fed.6 A 2010 cost analysis showed that increasing exclusive breastfeeding in the United States could prevent 911 excess deaths, 447 of which would be due to SIDS.21 This more recent meta-analysis would indicate the number of deaths related to formula feeding is likely much higher.
Furthermore, some research suggests that when infants are breastfed and when alcohol, drugs, and smoking are not involved, some aspects of bedsharing may be potentially protective against SIDS and suffocation. One survey has found that many parents have discovered acute life-threatening events in their infants only because they were next to them and could stimulate them from prolonged apneic episodes.22
Bedsharing breastfeeding mothers and their infants sleep very differently from formula-feeding mothers and do not have the same risks.23 Breastfeeding mothers and infants sleep in synchrony, with the mother and infant and oriented toward one another.23,24 Compared with formula-feeding mothers, breastfeeding mothers typically keep their babies away from pillows, placing their babies below their shoulders while raising their own arms above them. Breastfed infants are more likely to be positioned with their faces toward their mothers, minimizing the likelihood that they will be prone.25 Among breastfeeding infants, bedsharing promotes infant arousals.26 Breastfeeding mothers but not formula-feeding mothers typically tuck their legs up and lie on their sides to face their infants in ways that can prevent accidental overlying.27 Bedsharing formula-feeding infants are thus at higher risk of suffocation deaths than breastfeeding infants, as well being at higher risk of SIDS.
In addition, considerable research supports biological evidence that bedsharing may facilitate breastfeeding and that breastfeeding mothers are more likely to share a bed with their infants.28–30 When breastfeeding mothers bedshare, they get more sleep than if the infant sleeps separately.31,32 There is also evidence that when breastfeeding mothers try to avoid bedsharing, they either end up giving formula or start bedsharing anyway.2
Current U.S. safe sleep recommendations against bedsharing come almost exclusively from the AAP position, with far-reaching influence and implications.
It is thus important to examine the sources from which the AAP statement draws its sleep recommendations. The 2011 AAP statement reads, “Infants should not be placed on beds for sleep due to risk of suffocation or entrapment,” with two references for support, Ostfeld et al.33 (published in 2006) and Scheers et al.18 (published in 2003). Both of these studies have significant flaws. The study of Ostfeld et al.33 lumps sofas in with adult beds and fails to include alcohol or drug use by parents. The study of Scheers et al.18 also conflates sofas and other highly risky sleep surfaces with beds and fails to include smoking, alcohol, or drugs or feeding method.
As for its 2011 bedsharing recommendation, the AAP states that “AAP does not recommend any specific bed-sharing situation as safe.” They use four citations: Blair et al.34 (published in 1999), Carpenter et al.13 (published in 2004), Tappin et al.35 (published in 2005), and Mitchell and Thompson36 (published in 1995). The study of Blair et al.34 found that there is no increased risk for any infants of any age of parents who do not smoke. The study of Carpenter et al.13 noted that “for mothers who did not smoke during pregnancy, the odds ratio for bedsharing was very small.” The study of Tappin et al.35 did not collect data on maternal alcohol use and at times counted a death as bedsharing even when it occurred in a crib, as long as the infant had spent some time in his or her parent's bed earlier that night. The study of Mitchell and Thompson36 adjusted for all major risks but alcohol and found “if the mother is a non-smoker, there appears to be a small increased risk of bedsharing,” with a relative risk of 2.49 (95% confidence interval, 1.57, 4.29). Thus, two studies had omitted alcohol, and two showed risks too small to arguably justify the AAP's broad recommendations.
In addition, the 2011 AAP recommendations omit other compelling data around bedsharing. The data showing 447 excess deaths per year related to suboptimal breastfeeding21 were not cited, despite the fact that this article was widely publicized in the mainstream media in April 2010. The AAP statement omitted the 2010 survey of nearly 5,000 mothers showing that large numbers of mothers are unintentionally falling asleep on sofas while attempting to avoid bedsharing.10 It omits compelling data that recommendations to avoid bedsharing interfere with breastfeeding.1,2,37
AAP recommendations also ignore the weight of the evidence pointing toward a physiologic imperative for breastfeeding mothers to sleep with their infants. Infants require frequent feedings around the clock because of the nutritional content of human milk. In addition, as with other mammals, human mothers and their newborns have a need for close physical contact during sleep for thermoregulation, and both experience stress if separated.27,38–41 Maternal oxytocin released during breastfeeding may induce maternal somnolence. Furthermore, parents' reasons for bedsharing around the world include facilitating breastfeeding, meeting emotional needs of the mother and infant, monitoring and need to protect the infant, tradition, and disagreeing with danger.37,42,43 In one inner city population, mothers were not influenced by healthcare providers advising them never to bedshare.42 For all these reasons, advice never to bedshare relies on parents to suppress an overwhelming biologic imperative. Advice never to bedshare is thus unrealistic and unfeasible.
It is not even clear that cribs are indeed the safest place for an infant to sleep. If one examines cribs using an intention-to-treat analysis, the fact that many parents fall asleep on sofas while avoiding feeding their infants in bed in order to use cribs may mean that cribs may ultimately be less safe than their parents' beds. More research is needed.
If routine bedsharing is a risk factor for death in babies of nonsmoking breastfeeding mothers, it is small and greatly overshadowed by more potent risk factors. If we really want to lower the risk of sleep-related infant death in the United States, we must focus instead on those other risk factors: smoking, falling asleep on sofas, formula feeding, sleeping unattended, parental alcohol and drug use, and poverty. Campaigns to discourage bedsharing are taking up a disproportionate amount of resources better spent on addressing these other risk factors. It is important to educate parents on how to share a bed safely, as parents have stated they would appreciate this advice42 and because bedsharing is widespread.10,44–46
Public health efforts must address the reality that tired parents must feed their infants at night somewhere and that sofas are highly risky places for parents to fall asleep with their infants, especially if parents are smokers or under the influence of alcohol or drugs. Safe sleep messages must also recognize that breastfeeding infants and formula-feeding infants do not sleep the same way and do not share the same risks when bedsharing.
Safe sleep messages must also take into account the impact they may have on breastfeeding, which has wide-ranging public health impact aside from SIDS. A lack of breastfeeding is associated with childhood obesity, maternal breast cancer, maternal diabetes, and maternal heart disease, all of which are dependent on the duration of breastfeeding.47,48 Any message that may inadvertently decrease breastfeeding duration or exclusivity for the sake of one disease must take into account the entire public health picture.
The issues around safe sleep are complex. No infant sleep environment is completely safe. The only evidence-based universal advice is that sofas are hazardous places for adults to sleep with infants, that exposure to smoke, both prenatal and postnatal, increases the risk of death, and that sleeping next to an impaired caregiver increases the risk of death.
As with any social marketing campaign, all messaging must be crafted using careful testing and evaluation with the target audience to avoid unintended negative consequences, including impact on breastfeeding rates, or falling asleep in more dangerous situations than parental beds, such as sofas. In addition, there must be plans for periodic re-evaluation of any campaign and a willingness to change the messaging if it is ineffective or having unintended consequences.
Making a real difference in infant deaths will require a completely new way of addressing this issue and may need to go well beyond social marketing on safe sleep. We must prioritize research on the reasons why parents fall asleep on sofas with their infants in order minimize the growing number of these tragic deaths. Although there have been many research studies on bedsharing, to our knowledge, there has not been a single study on the reasons for sofa-sharing despite the growing numbers of these deaths.
Investment in programs to aggressively support maternal smoking cessation and curb substance use and smoking among new parents may be necessary to decrease infant deaths.
Finally, infant deaths could be reduced by stepping up measures to support breastfeeding, including doing away with aggressive marketing of infant formula, especially in hospitals and by healthcare organizations. With hundreds of deaths per year attributable to infant formula, especially due to SIDS, we must eliminate conflicts of interest between formula companies and organizations dedicated to the health of children.
M.B. received research funding from the W.K. Kellogg Foundation for research on economics and breastfeeding. L.J.S. received one-time funding from La Leche League International for co-authoring Sweet Sleep: Nighttime and Naptime Strategies for the Breastfeeding Family, published by Ballantine Books.
1. PS Blair, J Heron, PJ Fleming. Relationship between bed sharing and breastfeeding: longitudinal, population-based analysis. Pediatrics 2010;126:e1119–e1126.
2. HL Ball. Breastfeeding, bed-sharing, and infant sleep. Birth 2003;30:181–188.
3. Task Force on Sudden Infant Death Syndrome; RY Moon. SIDS and other sleep-related infant deaths: Expansion of recommendations for a safe infant sleeping environment. Pediatrics 2011;128:1030–1039.
4. American Academy of Pediatrics Task Force on Sudden Infant Death Syndrome. 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;116:1245–1255.
5. RY Moon, L Fu. Sudden infant death syndrome: An update. Pediatr Rev 2012;33:314–320.
6. FR Hauck, JM Thompson, KO Tanabe, et al. Breastfeeding and reduced risk of sudden infant death syndrome: A meta-analysis. Pediatrics 2011;128:103–110.
7. PS Blair, P Sidebotham, PJ Berry, et al. Major epidemiological changes in sudden infant death syndrome: A 20-year population-based study in the UK. Lancet 2006;367:314–319.
8. EA Mitchell, BJ Taylor, RP Ford, et al. Four modifiable and other major risk factors for cot death: The New Zealand study. J Paediatr Child Health 1992;28(Suppl 1):S3–S8.
9. PS Blair, P Sidebotham, C Evason-Coombe, et al. Hazardous cosleeping environments and risk factors amenable to change: Case-control study of SIDS in south west England. BMJ 2009;339:b3666.
10. K Kendall-Tackett, Z Cong, T Hale. Mother-infant sleep locations and nighttime feeding behavior: U.S. data from the survey of mothers' sleep and fatigue. Clin Lact 2010;1(Fall):27–31.
11. CK Shapiro-Mendoza, M Kimball, KM Tomashek, et al. US infant mortality trends attributable to accidental suffocation and strangulation in bed from 1984 through 2004: Are rates increasing? Pediatrics 2009;123:533–539.
12. HL Ball, E Moya, L Fairley, et al. Bed- and sofa-sharing practices in a UK biethnic population. Pediatrics 2012;129:e673–e681.
13. RG Carpenter, LM Irgens, PS Blair, et al. Sudden unexplained infant death in 20 regions in Europe: Case control study. Lancet 2004;363:185–191.
14. MH Blabey, BD Gessner. Infant bed-sharing practices and associated risk factors among births and infant deaths in Alaska. Public Health Rep 2009;124:527–534.
15. MM Vennemann, HW Hense, T Bajanowski, et al. Bed sharing and the risk of sudden infant death syndrome: Can we resolve the debate? J Pediatr 2012;160:44–48.e42.
16. R Carpenter, C McGarvey, EA Mitchell, et al. Bed sharing when parents do not smoke: Is there a risk of SIDS? An individual level analysis of five major case-control studies. BMJ Open 2013;3(5). pii: e002299. doi: 10.1136/bmjopen-2012-002299.
17. MM Vennemann, T Bajanowski, B Brinkmann, et al. Sleep environment risk factors for sudden infant death syndrome: The German Sudden Infant Death Syndrome Study. Pediatrics 2009;123:1162–1170.
18. NJ Scheers, GW Rutherford, JS Kemp. Where should infants sleep? A comparison of risk for suffocation of infants sleeping in cribs, adult beds, and other sleeping locations. Pediatrics 2003;112:883–889.
19. JD Colvin, V Collie-Akers, C Schunn, et al. Sleep environment risks for younger and older infants. Pediatrics 2014;134:e406–e412.
20. MM Vennemann, T Bajanowski, B Brinkmann, et al. Does breastfeeding reduce the risk of sudden infant death syndrome? Pediatrics 2009;123:e406–e410.
21. M Bartick, A Reinhold. The burden of suboptimal breastfeeding in the United States: A pediatric cost analysis. Pediatrics 2010;125:e1048–e1056.
22. JJ McKenna, LE Volpe. Sleeping with baby: An internet-based sampling of parental experiences, choices, perceptions, and interperetations in a Western industrialized context. Infant Child Dev 2007;16:359–385.
23. JJ McKenna, SS Mosko. Sleep and arousal, synchrony and independence, among mothers and infants sleeping apart and together (same bed): An experiment in evolutionary medicine. Acta Paediatr Suppl 1994;397:94–102.
24. C Richard, S Mosko, J McKenna, S Drummond. Sleeping position, orientation, and proximity in bedsharing infants and mothers. Sleep 1996;19:685–690.
25. S Mosko, C Richard, J McKenna, et al. Maternal proximity and infant CO2 environment during bedsharing and possible implications for SIDS research. Am J Phys Anthropol 1997;103:315–328.
26. S Mosko, C Richard, J McKenna. Infant arousals during mother-infant bed sharing: Implications for infant sleep and sudden infant death syndrome research. Pediatrics 1997;100:841–849.
27. JJ McKenna, T McDade. Why babies should never sleep alone: A review of the co-sleeping controversy in relation to SIDS, bedsharing and breast feeding. Paediatr Respir Rev 2005;6:134–152.
28. LT Gettler, JJ McKenna. Evolutionary perspectives on mother-infant sleep proximity and breastfeeding in a laboratory setting. Am J Phys Anthropol 2011;144:454–462.
29. JJ McKenna, SS Mosko, CA Richard. Bedsharing promotes breastfeeding. Pediatrics 1997;100:214–219.
30. JJ McKenna, HL Ball, LT Gettler. Mother-infant cosleeping, breastfeeding and sudden infant death syndrome: What biological anthropology has discovered about normal infant sleep and pediatric sleep medicine. Am J Phys Anthropol 2007;(Suppl 45):133–161.
31. SI Quillin, LL Glenn. Interaction between feeding method and co-sleeping on maternal-newborn sleep. J Obstet Gynecol Neonatal Nurs 2004;33:580–588.
32. T Doan, A Gardiner, CL Gay, et al. Breast-feeding increases sleep duration of new parents. J Perinat Neonatal Nurs 2007;21:200–206.
33. BM Ostfeld, H Perl, L Esposito, et al. Sleep environment, positional, lifestyle, and demographic characteristics associated with bed sharing in sudden infant death syndrome cases: A population-based study. Pediatrics 2006;118:2051–2059.
34. PS Blair, PJ Fleming, IJ Smith, et al. Babies sleeping with parents: Case-control study of factors influencing the risk of the sudden infant death syndrome. CESDI SUDI Research Group. BMJ 1999;319:1457–1461.
35. D Tappin, R Ecob, H Brooke. Bedsharing, roomsharing, and sudden infant death syndrome in Scotland: A case-control study. J Pediatr 2005;147:32–37.
36. EA Mitchell, JMD Thompson. Co-sleeping increases the risk of SIDS, but sleeping in the parents' bedroom lowers it. In: TO Rognum, ed. Sudden Infant Death Syndrome: New Trends in the Nineties. Scandinavian University Press, Oslo, 1995, pp. 266–269.
37. SD Buswell, DL Spatz. Parent-infant co-sleeping and its relationship to breastfeeding. J Pediatr Health Care 2007;21:22–28.
38. JL Heraghty, TN Hilliard, AJ Henderson, et al. The physiology of sleep in infants. Arch Dis Child 2008;93:982–985.
39. R Beijers, JM Riksen-Walraven, C de Weerth. Cortisol regulation in 12-month-old human infants: Associations with the infants' early history of breastfeeding and co-sleeping. Stress 2013;16:267–277.
40. MS Tollenaar, R Beijers, J Jansen, et al. Solitary sleeping in young infants is associated with heightened cortisol reactivity to a bathing session but not to a vaccination. Psychoneuroendocrinology 2012;37:167–177.
41. R Feldman, M Singer, O Zagoory. Touch attenuates infants' physiological reactivity to stress. Dev Sci 2010;13:271–278.
42. J Chianese, D Ploof, C Trovato, et al. Inner-city caregivers' perspectives on bed sharing with their infants. Acad Pediatr 2009;9:26–32.
43. TC Ward. Reasons for mother-infant bed-sharing: A systematic narrative synthesis of the literature and implications for future research. Matern Child Health J 2014 July 2 [Epub ahead of print]. doi: 10.1007/s10995-014-1557-1.
44. MB Lahr, KD Rosenberg, JA Lapidus. Maternal-infant bedsharing: Risk factors for bedsharing in a population-based survey of new mothers and implications for SIDS risk reduction. Matern Child Health J 2007;11:277–286.
45. K Jones-Vessey, M Avery, F Simsek. Infant Bed Sharing: Results from the North Carolina Pregnancy Risk Assessment Monitoring System Survey, 2009–2010. State Health Center for Health Statistics, Raleigh, NC, 2012.
46. E Declercq, C Sakala, MP Corry, et al. Listening to Mothers III: New Mothers Speak Out. Childbirth Connection, New York, 2013.
47. S Ip, M Chung, G Raman, et al. Breastfeeding and Maternal and Infant Health Outcomes in Developed Countries. Evidence Report/Technology Assessment Number 153. AHRQ Publication Number 07-E007. Agency for Healthcare Research and Quality, Rockville, MD, 2007.
48. EB Schwarz, RM Ray, AM Stuebe, et al. Duration of lactation and risk factors for maternal cardiovascular disease. Obstet Gynecol 2009;113:974–982.
49. RY Moon. SIDS and other sleep-related infant deaths: Expansion of recommendations for a safe infant sleeping environment. Pediatrics 2011;128:e1341–e1367.
50. K Zhang, X Wang. Maternal smoking and increased risk of sudden infant death syndrome: A meta-analysis. Legal Med 2013;15:115–121.
51. MM Vennemann, T Bajanowski, B Brinkmann, et al. Does breastfeeding reduce the risk of sudden infant death syndrome? Pediatrics 2009;123:e406–e410.
52. U.S. Department of Health and Human Services. The Surgeon General's Call to Action to Support Breastfeeding. Office of the Surgeon General, U.S. Department of Health and Human Services, Washington, DC, 2011.
53. PJ Fleming, R Gilbert, Y Azaz, et al. Interaction between bedding and sleeping position in the sudden infant death syndrome: A population based case-control study. BMJ 1990;301:85–89.
54. FR Hauck, SM Herman, M Donovan, et al. Sleep environment and the risk of sudden infant death syndrome in an urban population: The Chicago Infant Mortality Study. Pediatrics 2003;111:1207–1214.
55. HL Ball, MP Ward-Platt, E Heslop, et al. Randomised trial of infant sleep location on the postnatal ward. Arch Dis Child 2006;91:1005–1010.