Parent-infant bed-sharing behavior : Effects of feeding type and presence of father

Bedsharing among breastfeeding physicians: Results of a nationwide survey

INTRODUCTION

Bedsharing is common but advised against by the American Academy of Pediatrics. It is unknown if breastfeeding physicians bedshare more or less than the general population.

OBJECTIVES

To determine the prevalence of bedsharing among physicians, their reasons for bedsharing or not, and whether bedsharing was associated with a longer duration of breastfeeding.

METHODS

An online survey was adapted from surveys administered by the Centers for Disease Control and Prevention. The survey was administered to physicians and medical students who birthed children from October 2020 through August 2021. Respondents were asked to report on a singleton birth, and questions centered around sleep practices and breastfeeding. Survival analysis was used to examine the association between bedsharing and breastfeeding duration.

RESULTS

Of 546 respondents with bedsharing data, 68% reported some history of bedsharing, and 77% were in specialties that involved caring for pregnant people and/or infants. Those who bedshared breastfed an average of four months longer than those who never bedshared (18.08 versus 14.08 months p<0.001). The adjusted risk of breastfeeding cessation was markedly lower for those who bedshared compared to those who did not (Hazard Ratio 0.57, 95% Confidence Interval 0.45, 0.71). The primary reason for bedsharing was to breastfeed (73%); the primary reason for not bedsharing was safety concerns (92%). Among those who bedshared (n = 373), 52% did not inform their child's healthcare provider.

CONCLUSIONS

Bedsharing is common among our sample of mainly breastfeeding physicians, including those who care for pregnant people and/or infants. It is also associated with a longer duration of breastfeeding, which has implications for population health. Practicing bedsharing implies cognitive dissidence and may affect how physicians counsel about bedsharing. Additionally, lack of disclosure of bedsharing practices has implications for practical guidance about having open non-judgmental conversations and may be a missed opportunity to counsel on bedsharing safety.

Associations between bed-sharing in infancy and childhood internalizing and externalizing symptoms

Bed-sharing is a controversial but common parenting practice with claimed benefits for emotional and behavioral development. Using data from the UK Millennium Cohort Study (N = 16,599), this prospective study investigated whether bed-sharing at 9 months is associated with childhood internalizing and externalizing symptom trajectories. Children were grouped by their patterns of co-developing internalizing and externalizing symptoms from 3 to 11 years of age using a parallel process latent class growth analysis. There were no associations between bed-sharing at 9 months of age and internalizing and externalizing symptom trajectories across childhood. This finding suggests that bed-sharing at 9 months has no positive or negative influence on the development of internalizing and externalizing symptoms across childhood. Clinicians should inform parents that bed-sharing during the second half of the first year is unlikely to have an impact on the later emotional and behavioral development of the children.

Death from Failed Protection? An Evolutionary-Developmental Theory of Sudden Infant Death Syndrome

Sudden infant death syndrome (SIDS) has been mainly described from a risk perspective, with a focus on endogenous, exogenous, and temporal risk factors that can interact to facilitate lethal outcomes. Here we discuss the limitations that this risk-based paradigm may have, using two of the major risk factors for SIDS, prone sleep position and bed-sharing, as examples. Based on a multipronged theoretical model encompassing evolutionary theory, developmental biology, and cultural mismatch theory, we conceptualize the vulnerability to SIDS as an imbalance between current physiologic-regulatory demands and current protective abilities on the part of the infant. From this understanding, SIDS appears as a developmental condition in which competencies relevant to self-protection fail to develop appropriately in the future victims. Since all of the protective resources in question are bound to emerge during normal infant development, we contend that SIDS may reflect an evolutionary mismatch situation-a constellation in which certain modern developmental influences may overextend the child's adaptive (evolutionary) repertoire. We thus argue that SIDS may be better understood if the focus on risk factors is complemented by a deeper appreciation of the protective resources that human infants acquire during their normal development. We extensively analyze this evolutionary-developmental theory against the body of epidemiological and experimental evidence in SIDS research and thereby also address the as-of-yet unresolved question of why breastfeeding may be protective against SIDS.

The Role of Breastfeeding in Racial and Ethnic Disparities in Sudden Unexpected Infant Death: A Population-Based Study of 13 Million Infants in the United States

Sudden unexpected infant death (SUID) disproportionately affects non-Hispanic Black (NHB) and American Indian/Alaskan Native infants, who have lower rates of breastfeeding than other groups. Using 13,077,880 live-birth certificates and 11,942 linked SUID death certificates from 2015 through 2018, we calculated odds ratios and adjusted risk differences of SUID in infants who were not breastfed across 5 racial/ethnic strata in the United States. We analyzed mediation by not breastfeeding in the race/ethnicity-SUID association. The overall SUID rate was 0.91 per 1,000 live births. NHB and American Indian/Alaskan Native infants had the highest disparity in SUID relative to non-Hispanic White infants. Overall, not breastfeeding was associated with SUID (adjusted odds ratio (aOR), 1.14; 95% confidence interval (CI): 1.10, 1.19), and the adjusted risk difference was 0.12 per 1,000 live births. The aOR of not breastfeeding for SUID was 1.07 (95% CI: 1.00, 1.14) in NHB infants and 1.29 (95% CI: 1.14, 1.46) in Hispanic infants. Breastfeeding minimally explained the higher SUID risk in NHB infants (2.3% mediated) and the lower risk in Hispanic infants (2.1% mediated) relative to non-Hispanic White infants. Competing risks likely explain the lower aOR seen in NHB infants of not breastfeeding on SUID, suggesting that social or structural determinants must be addressed to reduce racial disparities in SUID.

Reasons mothers bedshare: A review of its effects on infant behavior and development

Bedsharing is controversial for nighttime caregiving in the U.S. today, as in most of the West. However, from the standpoint of evolutionary pediatrics, anthropology, and cultural psychology, bedsharing is not controversial at all, representing the context for human infant evolution and conferring a host of physiological benefits to the infant as well as the mother. In an effort to understand the rise in Western bedsharing in recent decades (and following Ball, 2002; McKenna & Volpe, 2007), Salm Ward (2015) systematically reviewed the literature on mother-infant bedsharing and identified ten reasons why mothers choose to bedshare: (1) breastfeeding, (2) comforting for mother or infant, (3) better/more sleep for infant or parent, (4) monitoring, (5) bonding/ attachment, (6) environmental reasons, (7) crying, (8) cultural or familial traditions, (9) disagree with danger, and (10) maternal instinct. The current paper offers the "review behind the review," highlighting the scientific evidence behind the reasons mothers give for their decision to bedshare, focusing on how mothers' decisions about infant sleep location influence infant behavior and development.

Sleep Consolidation, Sleep Problems, and Co-Sleeping: Rethinking Normal Infant Sleep as Species-Typical

Infants evolved in the context of close contact (including co-sleeping). Evolutionary context is rarely considered in psychological infant sleep research, and Western sleep researchers make assumptions about what optimal "normal" infant sleep is and how to achieve early, deep, infant sleep consolidation and avoid infant sleep problems. However, an evolutionary and anthropological view of infant sleep as species-typical recognizes that human evolution likely prepared the infant brain for optimal development within its evolutionary context - co-sleeping. Thus, "normal" infant sleep, sleep consolidation, and sleep problems should all be understood within the framework of co-sleeping infants, not the historically new-phenomenon of solitary-sleeping infants. Much work needs to be done in order to understand "normal" infant sleep as species-typical and how adaptive infants are to environments that stray from their evolutionary norm.

Fathers and Sleep: A Systematic Literature Review of Bidirectional Links Between Paternal Factors and Children's Sleep in the First Three Years of Life

Objective

During childhood, sleep problems are a common concern for parents and families. The literature on children’s sleep documents a strong association between parental factors and infant sleep quality. However, most studies have only examined maternal attitudes and behaviors. To systematically identify and assess the existing literature on the role of fathers in children’s sleep over the first three years of life.

Method

Studies were identified from January 1993 to July 2020 in four electronic databases, following PRIMSA guidelines.

Results

The initial search yielded a total of 657 records. Fifty-nine studies were full review, and 26 studies met all inclusion criteria and formed the basis for the review. Studies were divided into thematic groups as a function of the paternal variables they investigated: Extrinsic Parenting factors, Parent-child Interaction Context, and Distal Environmental Influences.

Conclusions

This review points up a range of paternal variables that can represent risk or protective factors for child sleep. Our results may help parents and healthcare practitioners to identify evidence-based knowledge about sleep. Furthermore, identifying paternal factors that contribute to sleep problems can usefully inform the design of individualized interventions.

A Nursing Perspective on Infant Bed-Sharing Using Multidisciplinary Theory Integration

The American Academy of Pediatrics recommends against bed-sharing between infants and caregivers due to an association with suffocation. Caregivers continue to share a bed with their infant despite these recommendations for a multitude of reasons. A close examination of the bed-sharing literature reveals that the debate is fundamentally about theoretical differences. The major theories used to frame this problem include the triple risk model of bed-sharing and evolutionary theories. Nurses are masters of multidisciplinary collaboration and are well positioned to unify the triple risk and evolutionary views of infant bed-sharing to guide future innovations in health care practice and research.

Bedsharing and Breastfeeding: The Academy of Breastfeeding Medicine Protocol #6, Revision 2019

A central goal of the Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.

An Integrated Analysis of Maternal-Infant Sleep, Breastfeeding, and Sudden Infant Death Syndrome Research Supporting a Balanced Discourse

Breastfeeding and the place of sleep for the mother and the infant have been controversial internationally due to reported concerns regarding infant deaths despite the known benefits of exclusive and prolonged breastfeeding, which are increased by breastfeeding at night. The aims of this integrated analysis were to (a) review breastfeeding and maternal and infant sleep research literature via historical, epidemiological, anthropological, and methodological lenses; (b) use this information to determine where we are currently in safeguarding both infant lives and breastfeeding; and (c) postulate the direction that research might take from this point forward to improve our knowledge and inform our policy and practice. Despite well-meaning but unsuccessful campaigns in some countries to dissuade parents from sleeping with their babies, many breastfeeding mothers and caregivers do sleep with their infants whether intentionally or unintentionally. Taking cultural contexts and socio-ecological circumstances into consideration, data supports policies to counsel parents and caregivers on safe sleep practices, including bed-sharing in non-hazardous circumstances, particularly in the absence of parental smoking, recent parental alcohol consumption, or sleeping next to an adult on a sofa. Further research with appropriate methodology is needed to drill down on actual rates of infant deaths, paying close attention to the definitions of deaths, the circumstances of the deaths, and confounding factors, in order to ensure we have the best information with which to derive public health policy. Introduction and use of the concept of "breastsleeping" is a plausible way to remove the negative connotations of "co-sleeping" and redirect ongoing data-driven discussions and education of best practices of breastfeeding and sleep.

Sudden infant death and social justice: A syndemics approach

Sudden unexpected infant death (SUID) and sudden infant death syndrome (SIDS) prevention has focused on modifying individual behavioural risk factors, especially bedsharing. Yet these deaths are most common among poor and marginalized people in wealthy countries, including U.S. Blacks, American Indians/Alaskan Natives, New Zealand Māori, Australian Aborigines, indigenous Canadians, and low-income British people. The United States now has the world's highest prevalence of SUID/SIDS, where even Whites' SIDS prevalence now approaches that of the Māori. Using public databases and the literature, we examine SUID/SIDS prevalence and the following risk factors in selected world populations: maternal smoking, preterm birth, alcohol use, poor prenatal care, sleep position, bedsharing, and formula feeding. Our findings suggest that risk factors cluster in high-prevalence populations, many are linked to poverty and discrimination and have independent effects on perinatal outcomes. Moreover, populations with the world's lowest rates of SUID/SIDS have low income-inequality or high relative wealth, yet have high to moderate rates of bedsharing. Employing syndemics theory, we suggest that disproportionately high prevalence of SUID/SIDS is primarily the result of socially driven, co-occurring epidemics that may act synergistically to amplify risk. SUID must be examined through the lens of structural inequity and the legacy of historical trauma. Emphasis on bedsharing may divert attention from risk reduction from structural interventions, breastfeeding, prenatal care, and tobacco cessation. Medical organizations play an important role in advocating for policies that address the root causes of infant mortality via poverty and discrimination interventions, tobacco control, and culturally appropriate support to families.

The influence of bed-sharing on infant physiology, breastfeeding and behaviour: A systematic review

This review aimed to better understand the underlying physiology of the risks and benefits of bed-sharing. Eight databases were searched using terms relating to adult-infant/baby, bed-sharing/co-sleeping combined with outcome terms for physiology, sleep, cardiovascular, respiratory, temperature and behaviour. Of 836 papers identified, 59 papers representing 48 cohorts met inclusion criteria. Objective data using various methodologies were available in 27 papers and subjective data in 32 papers. Diverse measures were reported using variable definitions of bed-sharing. Identified physiological and behavioural differences between bed-sharing and cot-sleeping included increased behavioural arousals, warmer in-bed temperatures and increased breastfeeding duration in bedshare infants as well as differences in infant overnight sleep architecture, cardiorespiratory control and cortisol responses to stress. We concluded that many differences are context-specific, and dependent on the subjective view of the parents and their cultural values. Objective risk arises if the infant is unable to mount an appropriate physiological or behavioural response to their micro-environment. More studies in the bed-sharing setting are needed to identify infant risk, the potential benefits of a safer environment, and how bed-sharing interacts with infant care practices other than sleep.

A Multispecies Approach to Co-Sleeping : Integrating Human-Animal Co-Sleeping Practices into Our Understanding of Human Sleep

Human sleeping arrangements have evolved over time and differ across cultures. The majority of adults share their bed at one time or another with a partner or child, and many also sleep with pets. In fact, around half of dog and cat owners report sharing a bed or bedroom with their pet(s). However, interspecies co-sleeping has been trivialized in the literature relative to interpersonal or human-human co-sleeping, receiving little attention from an interdisciplinary psychological perspective. In this paper, we provide a historical outline of the "civilizing process" that has led to current sociocultural conceptions of sleep as an individual, private function crucial for the functioning of society and the health of individuals. We identify similar historical processes at work in the formation of contemporary constructions of socially normative sleeping arrangements for humans and animals. Importantly, since previous examinations of co-sleeping practices have anthropocentrically framed this topic, the result is an incomplete understanding of co-sleeping practices. By using dogs as an exemplar of human-animal co-sleeping, and comparing human-canine sleeping with adult-child co-sleeping, we determine that both forms of co-sleeping share common factors for establishment and maintenance, and often result in similar benefits and drawbacks. We propose that human-animal and adult-child co-sleeping should be approached as legitimate and socially relevant forms of co-sleeping, and we recommend that co-sleeping be approached broadly as a social practice involving relations with humans and other animals. Because our proposition is speculative and derived from canine-centric data, we recommend ongoing theoretical refinement grounded in empirical research addressing co-sleeping between humans and multiple animal species.

Babies in boxes and the missing links on safe sleep: Human evolution and cultural revolution

Concerns about bedsharing as a risk for sudden infant death syndrome and other forms of sleep-associated infant death have gained prominence as a public health issue. Cardboard "baby boxes" are increasingly promoted to prevent infant death through separate sleep, despite no proof of efficacy. However, baby boxes disrupt "breastsleeping" (breastfeeding with co-sleeping) and may undermine breastfeeding. Recommendations enforcing separate sleep are based on 20th century Euro-American social norms for solitary infant sleep and scheduled feedings via bottles of cow's milk-based formula, in contrast to breastsleeping, an evolutionary adaptation facilitating the survival of mammalian infants for millennia. Interventions that aim to prevent bedsharing, such as the cardboard baby box, fail to consider the implications of evolutionary biology or of ethnocentrism in sleep guidance. Moreover, the focus on bedsharing neglects more potent risks such as smoking, drugs, alcohol, formula feeding, and poverty. Distribution of baby boxes may divert resources and attention away from addressing these other risk factors and lead to a false sense of security wherein we overlook that sudden unexplained infant deaths also occur in solitary sleep environments. Recognizing breastsleeping as the evolutionary and cross-cultural norm entails re-evaluating our research and policy priorities, such as providing greater structural support for families, supporting breastfeeding and safe co-sleeping, investigating ways to safely minimize separation for formula-fed infants, and mitigating the potential harms of mother-infant separation when breastsleeping is disrupted. Resources would be better spent addressing such questions rather than on a feel-good solution such as the baby box.

Infant Safe Sleep Interventions, 1990-2015: A Review

Sleep-related infant deaths remain a major public health issue. Multiple interventions have been implemented in efforts to increase adherence to safe sleep recommendations. We conducted a systematic review of the international research literature to synthesize research on interventions to reduce the risk of sleep-related deaths and their effectiveness in changing infant sleep practices. We searched PubMed, CINAHL, PsycINFO, and Google Scholar for peer-reviewed articles published between 1990 and 2015 which described an intervention and reported results. Twenty-nine articles were included for review. Studies focused on infant caregivers, health care professionals, peers, and child care professionals. Targeted behaviors included sleep position, location, removing items from the crib, breastfeeding, smoke exposure, clothing, pacifier use, and knowledge of Sudden Infant Death Syndrome. Most articles described multi-faceted interventions, including: one-on-one or group education, printed materials, visual displays, videos, and providing resources such as cribs, pacifiers, wearable blankets, and infant t-shirts. Two described public education campaigns, one used an educative questionnaire, and one encouraged maternal note taking. Health professional interventions included implementing safe sleep policies, in-service training, printed provider materials, eliciting agreement on a Declaration of Safe Sleep Practice, and sharing adherence data. Data collection methods included self-report via surveys and observational crib audits. Over half of the studies utilized comparison groups which helped determine effectiveness. Most articles reported some degree of success in changing some of the targeted behaviors; no studies reported complete adherence to recommendations. Future studies should incorporate rigorous evaluation plans, utilize comparison groups, and collect demographic and collect follow-up data.

Infant Sleep Location and Breastfeeding Practices in the United States, 2011-2014

OBJECTIVE

To describe the prevalence of breastfeeding and sleep location practices among US mothers and the factors associated with these behaviors, including advice received regarding these practices.

METHODS

A nationally representative sample of 3218 mothers who spoke English or Spanish were enrolled at a sample of 32 US birth hospitals between January 2011 and March 2014.

RESULTS

Exclusive breastfeeding was reported by 30.5% of mothers, while an additional 29.5% reported partial breastfeeding. The majority of mothers, 65.5%, reported usually room sharing without bed sharing, while 20.7% reported bed sharing. Compared to mothers who room shared without bed sharing, mothers who bed shared were more likely to report exclusive breastfeeding (adjusted odds ratio 2.46, 95% confidence interval 1.76, 3.45) or partial breastfeeding (adjusted odds ratio 1.75, 95% confidence interval 1.33, 2.31). The majority of mothers reported usually room sharing without bed sharing regardless of feeding practices, including 58.2% of exclusively breastfeeding mothers and 70.0% of nonbreastfeeding mothers. Receiving advice regarding sleep location or breastfeeding increased adherence to recommendations in a dose response manner (the adjusted odds of room sharing without bed sharing and exclusive breastfeeding increased as the relevant advice score increased); however, receiving advice regarding sleep location did not affect feeding practices.

CONCLUSIONS

Many mothers have not adopted the recommended infant sleep location or feeding practices. Receiving advice from multiple sources appears to promote adherence in a dose response manner. Many women are able to both breastfeed and room share without bed sharing, and advice to adhere to both of these recommendations did not decrease breastfeeding rates.

Bed-sharing by breastfeeding mothers: who bed-shares and what is the relationship with breastfeeding duration?

AIM

To explore the link between breastfeeding duration and bed-sharing frequency among women reporting a prenatal intention to breastfeed.

METHODS

About 870 participants in a randomised breastfeeding trial, recruited at mid-pregnancy, provided weekly snapshots of breastfeeding and bed-sharing behaviour for 26 weeks following birth. Strength of prenatal breastfeeding intent was recorded at recruitment using Likert-type scales.

RESULTS

Outcomes were frequency of bed-sharing at home for at least one hour per week, and time to cessation of breastfeeding. There were insufficient data to classify bed-sharing pattern in 192/870 (22%) of mothers. Of the remainder, 44% (299/678) of participants 'rarely' or 'never' bed-shared, 28% (192/678) did so 'intermittently' and 28% (187/678) did so 'often'. These three groups did not differ significantly in marital status, income, infant gestational age, maternal age or delivery mode. Significantly, more participants who bed-shared 'often' reported strong prenatal breastfeeding intent (70% vs. 57% and 56% for 'intermittent' and 'rare' bed-share groups) and attached high prenatal importance to breastfeeding (95% vs. 87% and 82%). Significantly, more women who bed-shared frequently were breastfeeding at 6 months (p < 0.0001) than those who intermittently or rarely/never bed-shared.

CONCLUSION

Women with strong motivation to breastfeed frequently bed-share. Given the complex relationship between bed-sharing and sudden infant death syndrome (SIDS) appropriate guidance balancing risk minimisation with support for breastfeeding mothers is crucial.

The relationship between planned and reported home infant sleep locations among mothers of late preterm and term infants

To compare maternal report of planned and practiced home sleep locations of infants born late preterm (34 0/7 to 36 6/7 gestational weeks) with those infants born term (≥37 0/7 gestational weeks) over the first postpartum month. Open-ended semi-structured maternal interviews were conducted in a US hospital following birth and by phone at 1 month postpartum during 2010-2012. Participants were 56 mother-infant dyads: 26 late preterm and 30 term. Most women planned to room share at home with their infants and reported doing so for some or all of the first postpartum month. More women reported bed sharing during the first postpartum month than had planned to do so in both the late preterm and term groups. The primary reason for unplanned bed sharing was to soothe nighttime infant fussiness. Those participants who avoided bed sharing at home commonly discussed their fear for infant safety. A few parents reported their infants were sleeping propped on pillows and co-sleeping on a recliner. Some women in both the late preterm and term groups reported lack of opportunity to obtain a bassinet prior to childbirth. The discrepancy between plans for infant sleep location at home and maternally reported practices were similar in late preterm and term groups. Close maternal proximity to their infants at night was derived from the need to assess infant well-being, caring for infants, and women's preferences. Bed sharing concerns related to infant safety and the establishment of an undesirable habit, and alternative arrangements included shared recliner sleep.

Parent-child bed-sharing: The good, the bad, and the burden of evidence

The practice of parent and child sharing a sleeping surface, or 'bed-sharing', is one of the most controversial topics in parenting research. The lay literature has popularized and polarized this debate, offering on one hand claims of dangers, and on the other, of benefits - both physical and psychological - associated with bed-sharing. To address the scientific evidence behind such claims, we systematically reviewed 659 published papers (peer-reviewed, editorial pieces, and commentaries) on the topic of parent-child bed-sharing. Our review offers a narrative walkthrough of the many subdomains of bed-sharing research, including its many correlates (e.g., socioeconomic and cultural factors) and purported risks or outcomes (e.g., sudden infant death syndrome, sleep problems). We found general design limitations and a lack of convincing evidence in the literature, which preclude making strong generalizations. A heat-map based on 98 eligible studies aids the reader to visualize world-wide prevalence in bed-sharing and highlights the need for further research in societies where bed-sharing is the norm. We urge for multiple subfields - anthropology, psychology/psychiatry, and pediatrics - to come together with the aim of understanding infant sleep and how nightly proximity to the parents influences children's social, emotional, and physical development.

Does cosleeping contribute to lower testosterone levels in fathers? Evidence from the Philippines

Because cross-species evidence suggests that high testosterone (T) may interfere with paternal investment, the relationships between men's transition to parenting and changes in their T are of growing interest. Studies of human males suggest that fathers who provide childcare often have lower T than uninvolved fathers, but no studies to date have evaluated how nighttime sleep proximity between fathers and their offspring may affect T. Using data collected in 2005 and 2009 from a sample of men (n = 362; age 26.0 ± 0.3 years in 2009) residing in metropolitan Cebu, Philippines, we evaluated fathers' T based on whether they slept on the same surface as their children (same surface cosleepers), slept on a different surface but in the same room (roomsharers), or slept separately from their children (solitary sleepers). A large majority (92%) of fathers in this sample reported practicing same surface cosleeping. Compared to fathers who slept solitarily, same surface cosleeping fathers had significantly lower evening (PM) T and also showed a greater diurnal decline in T from waking to evening (both p<0.05). Among men who were not fathers at baseline (2005), fathers who were cosleepers at follow-up (2009) experienced a significantly greater longitudinal decline in PM T over the 4.5-year study period (p<0.01) compared to solitary sleeping fathers. Among these same men, baseline T did not predict fathers' sleeping arrangements at follow-up (p>0.2). These results are consistent with previous findings indicating that daytime father-child interaction contributes to lower T among fathers. Our findings specifically suggest that close sleep proximity between fathers and their offspring results in greater longitudinal decreases in T as men transition to fatherhood and lower PM T overall compared to solitary sleeping fathers.

Scientific consensus forum to review the evidence underpinning the recommendations of the Australian SIDS and Kids Safe Sleeping Health Promotion Programme--October 2010

This paper summarises a 1-day scientific consensus forum that reviewed the evidence underpinning the Australian SIDS and Kids Safe Sleeping Health Promotion Programme. The focus was on each of the potentially modifiable risk factors for sudden unexpected deaths in infancy, including sudden infant death syndrome (SIDS) and fatal sleeping accidents. In particular infant sleeping position, covering of the face, exposure to cigarette smoke, room sharing, unsafe sleeping environments, bed sharing, immunisation, breastfeeding, pacifier use and Indigenous issues were discussed in depth. The participants recommended that future 'Reducing the Risk' campaign messages should focus on back to sleep, face uncovered, avoidance of cigarette smoke before and after birth, safe sleeping environment, room sharing and sleeping baby in own cot.

Nighttime parenting strategies and sleep-related risks to infants

A large social science and public health literature addresses infant sleep safety, with implications for infant mortality in the context of accidental deaths and Sudden Infant Death Syndrome (SIDS). As part of risk reduction campaigns in the USA, parents are encouraged to place infants supine and to alter infant bedding and elements of the sleep environment, and are discouraged from allowing infants to sleep unsupervised, from bed-sharing either at all or under specific circumstances, or from sofa-sharing. These recommendations are based on findings from large-scale epidemiological studies that generate odds ratios or relative risk statistics for various practices; however, detailed behavioural data on nighttime parenting and infant sleep environments are limited. To address this issue, this paper presents and discusses the implications of four case studies based on overnight observations conducted with first-time mothers and their four-month old infants. These case studies were collected at the Mother-Baby Behavioral Sleep Lab at the University of Notre Dame USA between September 2002 and June 2004. Each case study provides a detailed description based on video analysis of sleep-related risks observed while mother-infant dyads spent the night in a sleep lab. The case studies provide examples of mothers engaged in the strategic management of nighttime parenting for whom sleep-related risks to infants arose as a result of these strategies. Although risk reduction guidelines focus on eliminating potentially risky infant sleep practices as if the probability of death from each were equal, the majority of instances in which these occur are unlikely to result in infant mortality. Therefore, we hypothesise that mothers assess potential costs and benefits within margins of risk which are not acknowledged by risk-reduction campaigns. Exploring why mothers might choose to manage sleep and nighttime parenting in ways that appear to increase potential risks to infants may help illuminate how risks occur for individual infants.

Functioning within a relationship: mother-infant synchrony and infant sleep

The aim of this study was to investigate the coupling of the biological system of infant sleep and the social system of mother-infant synchrony. Before birth and shortly after birth the systems appear to be connected, but it is unclear whether this remains the case over time. This study therefore examined whether infant sleep measured at 6 weeks and 5 months could predict mother-infant gaze synchrony after a social challenge at 5 months (N=84). Infant sleep was measured in terms of sleep bout duration, which normally increases during this period. Gaze was defined in terms of looking at each other's head simultaneously, known as gaze synchrony, or looking elsewhere. Results showed that infant sleep could predict the temporal dynamics of the mother-infant interaction in terms of flexibility of gaze pattern shifts. The larger the increase in sleep bout duration over age, the more flexible the interaction appeared to be. Maternal Age, type of feeding and change of feeding appeared to function as confounding variables in this relation. Infant sleep could not predict percentage of synchrony (central tendency measure) or the average sequence length of gaze patterns (temporal dynamic measure).

Evolutionary perspectives on mother-infant sleep proximity and breastfeeding in a laboratory setting

Human maternal and infant biology likely coevolved in a context of close physical contact and some approximation of frequent, "infant-initiated" breastfeeding. Still, mothers and infants commonly sleep apart from one another in many western societies, indicating a possible "mismatch" between cultural norms and infant biology. Here we present data from a 3-night laboratory-based study that examines differences in mother-infant sleep physiology and behavior when mothers and infants sleep together on the same surface (bedsharing) and apart in separate rooms (solitary). We analyze breastfeeding frequency and interval data from the first laboratory night (FN) for 52 complementary breastfeeding mothers and infants (26 total mother-infant pairs), of which 12 pairs were routine bedsharers (RB) and 14 were routine solitary sleepers (RS). RB infants were 12.0 ± 2.7 (SD) weeks old; RS infants were 13.0 ± 2.4 weeks old. On the FN, RB mother-infant pairs (while bedsharing) engaged in a greater number of feeds per night compared to RS (while sleeping alone) (P < 0.001). RB also showed lower intervals (min) between feeds relative to RS (P < 0.05). When we evaluated data from all three laboratory nights (n = 36), post hoc, RB breastfed significantly more often (P < 0.01) and showed a trend towards lower intervals between feeds (P < 0.10). Given the widely known risks associated with little or no breastfeeding, the demonstrated mutually regulatory relationship between bedsharing and breastfeeding should be considered in future studies evaluating determinants of breastfeeding outcomes.

Airway covering during bed-sharing

BACKGROUND

Parent-infant bed-sharing is a common practice in Western post-industrial nations with up to 50% of infants sleeping with their parents at some point during early infancy. However, researchers have claimed that infants may be at risk of suffocation or sudden infant death syndrome related to airway covering or compression in the bed-sharing environment. To further understand the role of airway covering and compression in creating risks for bed-sharing infants, we report here on a sleep-lab trial of two infant sleep conditions.

METHODS

In a sleep-lab environment 20 infants aged 2-3 months old slept in their parents' bed, and in a cot by the bed, on adjacent nights. Infants' oxygen saturation and heart rate were monitored physiologically while infant and parental behaviours were recorded via ceiling-mounted infra-red cameras. Infants served as their own controls. Continuous 8-h recordings were obtained for covering of infant external airways, levels of infant oxygen saturation, infant heart rate, evidence of parental compression/overlying of infant, circumstances leading up to potential infant airway obstruction, and parental awareness of and responses to infant airway covering.

RESULTS

The majority of infants (14/20) spent some part of the bed night with their airways (both mouth and nose) covered, compared with 2/20 on the cot night; however, no consistent effect on either oxygen saturation levels or heart rate was revealed, even during prolonged bouts of airway covering. All cases of airway covering were initiated by parents; 70% were terminated by parents, the remainder by infants. Seven bouts of potential compression were observed with parental limbs resting across infant bodies for lengthy periods, however, in only two cases was the full weight of a parental limb resting on an infant, both events lasting less than 15 s, both being terminated by infant movement.

CONCLUSION

Although numerous authors have suggested that bed-sharing infants face risks because of airway covering by bed-clothes or parental bodies, the present trial does not lend support to this hypothesis.

Mother-infant cosleeping, breastfeeding and sudden infant death syndrome: what biological anthropology has discovered about normal infant sleep and pediatric sleep medicine

Twenty years ago a new area of inquiry was launched when anthropologists proposed that an evolutionary perspective on infancy could contribute to our understanding of unexplained infant deaths. Here we review two decades of research examining parent-infant sleep practices and the variability of maternal and infant sleep physiology and behavior in social and solitary sleeping environments. The results challenge clinical wisdom regarding "normal" infant sleep, and over the past two decades the perspective of evolutionary pediatrics has challenged the supremacy of pediatric sleep medicine in defining what are appropriate sleep environments and behaviors for healthy human infants. In this review, we employ a biocultural approach that integrates diverse lines of evidence in order to illustrate the limitations of pediatric sleep medicine in adopting a view of infants that prioritizes recent western social values over the human infant's biological heritage. We review what is known regarding infant sleeping arrangements among nonhuman primates and briefly explore the possible paleoecological context within which early human sleep patterns and parent-infant sleeping arrangements might have evolved. The first challenges made by anthropologists to the pediatric and SIDS research communities are traced, and two decades of studies into the behavior and physiology of mothers and infants sleeping together are presented up to the present. Laboratory, hospital and home studies are used to assess the biological functions of shared mother-infant sleep, especially with regard to breastfeeding promotion and SIDS reduction. Finally, we encourage other anthropologists to participate in pediatric sleep research using the unique skills and insights anthropological data provide. By employing comparative, evolutionary and cross-cultural perspectives an anthropological approach stimulates new research insights that influence the traditional medical paradigm and help to make it more inclusive. That this review will potentially stimulate similar research by other anthropologists is one obvious goal. That this article might do so makes it ever more possible that anthropologically inspired work on infant sleep will ultimately lead to infant sleep scientists, pediatricians, and parents becoming more informed about the consequences of caring for human infants in ways that are not congruent with their evolutionary biology.

Randomised trial of infant sleep location on the postnatal ward

OBJECTIVE

To determine whether postnatal mother-infant sleep proximity affects breastfeeding initiation and infant safety.

DESIGN

Randomised non-blinded trial analysed by intention to treat.

SETTING

Postnatal wards of the Royal Victoria Hospital (RVI), Newcastle upon Tyne, UK.

PARTICIPANTS

64 newly delivered mother-infant dyads with a prenatal intention to breastfeed (vaginal deliveries, no intramuscular or intravenous opiate analgesics taken in the preceding 24 h).

INTERVENTION

Infants were randomly allocated to one of three sleep conditions: baby in mother's bed with cot-side; baby in side-car crib attached to mother's bed; and baby in stand-alone cot adjacent to mother's bed.

MAIN OUTCOME MEASURES

Breastfeeding frequency and infant safety observed via night-time video recordings.

RESULTS

During standardised 4-h observation periods, bed and side-car crib infants breastfed more frequently than stand-alone cot infants (mean difference (95% confidence interval (CI)): bed v stand-alone cot = 2.56 (0.72 to 4.41); side-car crib v stand-alone cot = 2.52 (0.87 to 4.17); bed v side-car crib = 0.04 (-2.10 to 2.18)). No infant experienced adverse events; however, bed infants were more frequently considered to be in potentially adverse situations (mean difference (95% CI): bed v stand-alone cot = 0.13 (0.03 to 0.23); side-car crib v stand-alone cot = 0.04 (-0.03 to 0.12); bed v side-car crib = 0.09 (-0.03-0.21)). No differences were observed in duration of maternal or infant sleep, frequency or duration of assistance provided by staff, or maternal rating of postnatal satisfaction.

CONCLUSION

Suckling frequency in the early postpartum period is a well-known predictor of successful breastfeeding initiation. Newborn babies sleeping in close proximity to their mothers (bedding-in) facilitates frequent feeding in comparison with rooming-in. None of the three sleep conditions was associated with adverse events, although infrequent, potential risks may have occurred in the bed group. Side-car cribs are effective in enhancing breastfeeding initiation and preserving infant safety in the postnatal ward.

Differences in infant and parent behaviors during routine bed sharing compared with cot sleeping in the home setting

OBJECTIVES

To observe the behavior of infants sleeping in the natural physical environment of home, comparing the 2 different sleep practices of bed sharing and cot sleeping quantifying to factors that have been identified as potential risks or benefits.

METHODS

Forty routine bed-sharing infants, aged 5-27 weeks were matched for age and season of study with 40 routine cot-sleeping infants. Overnight video and physiologic data of bed-share infants and cot-sleep infants were recorded in the infants' own homes. Sleep time, sleep position, movements, feeding, blanket height, parental checks, and time out of the bed or cot were logged.

RESULTS

The total sleep time was similar in both groups (bed-sharing median: 8.6 hours; cot-sleeping median: 8.2 hours). Bed-sharing infants spent most time in the side position (median: 5.7 hours, 66% of sleep time) and most commonly woke at the end of sleep in this position, whereas cot-sleeping infants most commonly slept supine (median: 7.5 hours, 100%) and woke at the end of sleep in the supine position. Prone sleep was uncommon in both groups. Head covering above the eyes occurred in 22 bed-sharing infants and 1 cot-sleeping infant. Five of these bed-sharing infants were head covered at final waking time, but the cot-sleeping infant was not. Bed-sharing parents looked at or touched their infant more often (median: 11 vs 4 times per night) but did not always fully wake to do so. Movement episodes were shorter in the bed-sharing group as was total movement time (37 vs 50 minutes respectively), whereas feeding was 3.7 times more frequent in the bed-sharing group than the cot-sleeping group.

CONCLUSIONS

Bed-share infants without known risk factors for sudden infant death syndrome (SIDS) experience increased maternal touching and looking, increased breastfeeding, and faster and more frequent maternal responses. This high level of interaction is unlikely to occur if maternal arousal is impaired, for example, by alcohol or overtiredness. Increased head covering and side sleep position occur during bed-sharing, but whether these factors increase the risk of SIDS, as they do in cot sleeping, requires further investigation.