Co-sleeping as a proximal context for infant development: The importance of physical touch

Sources of attitudes towards parent-child co-sleeping and their effects: A systematic scoping review

Parent-child co-sleeping is a common practice in many cultures, although in Western countries, families who engage in parent-child co-sleeping can encounter attitudes about co-sleeping that feel critical from the people around them, as it is not commonly accepted and often stigmatized. This systematic scoping review examined and synthesized the available literature on the attitudes about parent-child co-sleeping that people encounter, their origins, and their effect on parents' own attitudes and behaviors. A total of 9796 abstracts were screened, and 33 studies were included. While the scope of the literature on this topic was narrow, this review demonstrated that parents/caregivers mostly encounter encouraging attitudes about co-sleeping from their extended family members and within their culture and discouraging attitudes from healthcare professionals. Findings suggest that encouraging attitudes enhance the likelihood of parents engaging and continuing with co-sleeping behavior, while discouraging attitudes can lead to the avoidance of parents discussing sleep with their healthcare professionals and can cause conflicts with other family members, including partners. Based on these findings, we conclude that further research is needed in several areas related to co-sleeping in Western culture, most specifically in how external attitudes influence the decision to co-sleep, as well as other behaviors and cognitions such as engagement with healthcare professionals, family satisfaction, parental self-efficacy, and overall mental health.

Association between co-sleeping in the first year of life and preschoolers´ sleep patterns

This study aimed to investigate the association between co-sleeping practiced during the first year of life and preschoolers' sleep patterns. A cross-sectional study including toddlers was designed to analyze their sleep patterns. The Brief Infant Sleep Questionnaire, validated in Spanish, was used to measure sleep quality. A latent class analysis was performed to identify qualitative subgroups in the sample and explore the effects of co-sleeping. The sleep patterns of 276 children were analyzed. A total of 181 (65%) parents reported having practiced co-sleeping with their children. The latent class analysis identified a two-class solution with two different sleep patterns. One of them showed a worse quality sleep pattern, which had a significant association with having practiced co-sleeping during the first year of life, and with the fact that they were still sleeping in the parents' room, among other characteristics related to co-sleeping and parental concerns. Breastfeeding also showed association with a worse quality sleep pattern.  Conclusion: Based on the present findings, co-sleeping during the first year of life appears to be associated with poor sleep patterns in young preschoolers. What is Known: • Co-sleeping shows benefits for infants and parents, mainly facilitating successful breastfeeding. • Literature on the effect of co-sleeping in lately sleep quality in children and their parents is very limited. What is New: • Co-sleeping practiced during the first year of life could be associated with a worse sleep pattern measured with BISQ-E tool. • A balance between the correct practice of co-sleeping and the achievement of a healthy sleep routine in preschool should probably be part of parents' health education.

Instrument development and an intervention to increase parents' self-efficacy regarding their infant's sleep

OBJECTIVE

Many Swedish parents experience that their infant has sleeping problems. Parents' self-efficacy regarding their infants' sleep may play an important role in how they perceive these problems. This pilot study aimed to develop an instrument measuring parents' self-efficacy regarding their infant's sleep and to examine if parents' self-efficacy was affected by an intervention focusing on parental education.

METHOD

Mothers and fathers, at a maternity unit in Sweden, were drawn into either an intervention (n = 46) or a control (n = 42) group. The intervention group received a home visit from a nurse who provided information about infant sleep; the importance of attachment; and advice regarding sleep, breastfeeding and bed sharing, including guidelines for safe bed sharing. Three months later, the participants answered questions on background data, breastfeeding, sleep and self-efficacy.

RESULTS

The 11-item two-factor Uppsala Parental Self-Efficacy about Infant Sleep Instrument (UPPSEISI) was constructed to measure parents' perceived self-efficacy. In adjusted analyses, being in the intervention group was associated with a higher self-efficacy (P = 0.035), as were being a mother (P = 0.003) and being satisfied with one's own sleep (P = 0.007), while parents' own sleeping problems were associated with a lower self-efficacy (P = 0.015).

CONCLUSION

Importantly, parental education may increase parents' self-efficacy regarding their infant's sleep.

A narrative review of research linking non-sexual social touch to sleep quality

This narrative review describes the current state of the literature that has examined associations between non-sexual social touch (i.e., affectionate touch, touch therapies, touch with animals and inanimate objects that mimic social touch) and sleep quality. It also highlights areas for future research to clarify the links and to identify underlying mechanisms. Most existing studies have focussed on and shown positive effects of touch therapies (e.g., massage, therapeutic touch) on sleep quality in clinical populations. Although there are fewer studies examining how other forms of social touch are linked with sleep quality, the existing research provides preliminary evidence supporting affectionate touch (e.g., hugging, skin-to-skin contact) and tactile contact with animals (e.g., dogs) and objects that mimic social touch (e.g., robots, weighted blankets) as predictors of better sleep quality, while touch deprivation and touch aversion are associated with worse sleep quality. Informed by the existing literature, we additionally reviewed potential relational-cognitive (e.g., felt-security) and neurobiological (e.g., oxytocin) mechanisms likely to underlie associations between social touch and sleep quality. Overall, current research supports associations between non-sexual social touch and sleep quality. However, future research is needed to establish these links for specific forms of social touch (and in various populations), to test explanatory mechanisms, and to identify boundary conditions. Understanding associations between non-sexual social touch and sleep quality can inform the development of touch-based interventions to improve sleep quality and health.

Contextual considerations in infant sleep: Offering alternative interventions to families

Infant sleep problems are one of the commonly reported reasons parents seek professional help, yet what constitutes a "sleep problem" depends on the models used to explain the development of infant sleep. The current models are based on research conducted in the western context where infant solitary sleeping is the norm. Parent-child co-sleeping is the norm in many cultures around the world. We argue that the primary focus of current research on parent-child interactions as the mediating context for the development of infant sleep problems has inherently made these models and ensuing interventions less sensitive and applicable to infant sleep problems in the context of co-sleeping families. When families present for help with infant sleep difficulties, extinction based behavioral interventions or interventions focused on reducing parental presence at bedtime are commonly recommended. These recommendations may not always align with cultural values and parenting practices of all families, therefore precluding these families from getting necessary help. In attempting to provide families with choices that depart from behavioral based interventions, this paper draws on research and adapts current models to propose an alternative to conceptualize perceptions of infant sleep problems that may be sensitive to and applied across various cultural and personal contexts. We attempt to provide a rationale for interventions that are inclusive and sensitive to families where reduced parental nighttime responsiveness may not be a preferred choice.

Developmental Cascades Link Maternal-Newborn Skin-to-Skin Contact with Young Adults' Psychological Symptoms, Oxytocin, and Immunity; Charting Mechanisms of Developmental Continuity from Birth to Adulthood

Premature birth disrupts the continuity of maternal-newborn bodily contact, which underpins the development of physiological and behavioral support systems. Utilizing a unique cohort of mother-preterm dyads who received skin-to-skin contact (Kangaroo Care, KC) versus controls, and following them to adulthood, we examined how a touch-based neonatal intervention impacts three adult outcomes; anxiety/depressive symptoms, oxytocin, and secretory immunoglobulin A (s-IgA), a biomarker of the immune system. Consistent with dynamic systems' theory, we found that links from KC to adult outcomes were indirect, mediated by its effects on maternal mood, child attention and executive functions, and mother-child synchrony across development. These improvements shaped adult outcomes via three mechanisms; (a) "sensitive periods", where the infancy improvement directly links with an outcome, for instance, infant attention linked with higher oxytocin and lower s-IgA; (b) "step-by-step continuity", where the infancy improvement triggers iterative changes across development, gradually shaping an outcome; for instance, mother-infant synchrony was stable across development and predicted lower anxiety/depressive symptoms; and (c) "inclusive mutual-influences", describing cross-time associations between maternal, child, and dyadic factors; for instance, from maternal mood to child executive functions and back. Findings highlight the long-term impact of a birth intervention across development and provide valuable insights on the mechanisms of "developmental continuity", among the key topics in developmental research.

The sleeping brain's connectivity and family environment: characterizing sleep EEG coherence in an infant cohort

Brain connectivity closely reflects brain function and behavior. Sleep EEG coherence, a measure of brain's connectivity during sleep, undergoes pronounced changes across development under the influence of environmental factors. Yet, the determinants of the developing brain's sleep EEG coherence from the child's family environment remain unknown. After characterizing high-density sleep EEG coherence in 31 healthy 6-month-old infants by detecting strongly synchronized clusters through a data-driven approach, we examined the association of sleep EEG coherence from these clusters with factors from the infant's family environment. Clusters with greatest coherence were observed over the frontal lobe. Higher delta coherence over the left frontal cortex was found in infants sleeping in their parents' room, while infants sleeping in a room shared with their sibling(s) showed greater delta coherence over the central parts of the frontal cortex, suggesting a link between local brain connectivity and co-sleeping. Finally, lower occipital delta coherence was associated with maternal anxiety regarding their infant's sleep. These interesting links between sleep EEG coherence and family factors have the potential to serve in early health interventions as a new set of targets from the child's immediate environment.

Using complexity science to understand the role of co-sleeping (bedsharing) in mother-infant co-regulatory processes

Human infants spend most of their time sleeping, but over the first few years of life their sleep becomes regulated to coincide more closely with adult sleep (Galland et al., 2012; Paavonen et al., 2020). Evidence shows that co-sleeping played a role in the evolution of infant sleep regulation, as it is part of an ancient behavioral complex representing the biopsychosocial microenvironment in which human infants co-evolved with their mothers through millions of years of human history (Ball, 2003; McKenna 1986, 1990). This paper is a conceptual, interdisciplinary, integration of the literature on mother-infant co-sleeping and other mother-infant co-regulatory processes from an evolutionary (biological) perspective, using complexity science. Viewing the mother-infant dyad as a "complex adaptive system" (CAS) shows how the CAS fits assumptions of regulatory processes and reveals the role of the CAS in the ontogeny of mother-infant co-regulation of physiological (thermoregulation, breathing, circadian rhythm coordination, nighttime synchrony, and heart rate variability) and socioemotional (attachment and cortisol activity) development.

Co-Sleeping as a Protector against Malocclusion in the Primary Dentition: A Cross-Sectional Study

Mothers practice co-sleeping and breastfeeding simultaneously, for convenience and to strengthen bonding. Due to the scarcity of studies analyzing the impact of co-sleeping on primary dentition, this study aimed to analyze the possible effects of co-sleeping on children’s occlusion. In this cross-sectional study, mothers of 221 children aged 2−5 years who had been breastfed for less than 6 months completed a questionnaire about non-nutritive sucking habits. The WHO (World Health Organization) and IOTN-AC indices (the Aesthetic Component of the Index of Orthodontic Treatment Need) were used to assess malocclusion. The type of sagittal (dental and skeletal), transverse and vertical malocclusion was recorded. The non-co-sleeping group showed significantly higher pacifier use (p < 0.05), digital sucking (p < 0.05) and atypical swallowing (p < 0.05) habits. The non-co-sleeping group showed significantly higher mean scores on the IOTN-AC (p < 0.05) and WHO (p < 0.01), a significantly higher presence of canine class II (p < 0.05), anterior open bite (p < 0.05), posterior crossbite (p < 0.05), overbite (p < 0.05), skeletal class II (p < 0.01) and protrusion (p < 0.05). In conclusion, children who practice co-sleeping appear to have a lower frequency and duration of non-nutritive sucking habits. Co-sleeping may contribute to a lower development of malocclusions in children who are weaned early (before six months of age).

US fathers' reports of bonding, infant temperament and psychosocial stress based on family sleep arrangements

Background and objectives

Evolutionary-grounded sleep research has been critical to establishing the mutual dependence of breastfeeding and nighttime sleep proximity for mothers and infants. Evolutionary perspectives on cosleeping also often emphasize the emotional motivations for and potential benefits of sleep proximity, including for parent-infant bonding. However, this potential link between infant sleep location and bonding remains understudied for both mothers and fathers. Moreover, in Euro-American contexts bedsharing has been linked to family stress and difficult child temperament, primarily via maternal reports. We know relatively little about whether paternal psychosocial dynamics differ based on family sleep arrangements, despite fathers and other kin often being present in the cosleeping environment across cultures. Here, we aim to help address some of these gaps in knowledge pertaining to fathers and family sleep arrangements.

Methodology

Drawing on a sample of Midwestern U.S. fathers (N=195), we collected sociodemographic and survey data to analyze links between infant nighttime sleep location, paternal psychosocial well-being, father-infant bonding, and infant temperament. From fathers’ reports, families were characterized as routinely solitary sleeping, bedsharing, or roomsharing (without bedsharing).

Results

We found that routinely roomsharing or bedsharing fathers, respectively, reported stronger bonding than solitary sleepers. Bedsharing fathers also reported that their infants had more negative temperaments and also tended to report greater parenting-related stress due to difficulties with their children.

Conclusions

These cross-sectional results help to highlight how a practice with deep phylogenetic and evolutionary history, such as cosleeping, can be variably expressed within communities with the potential for family-dependent benefits or strains.

Evolutionary-grounded cosleeping research has elucidated the intimate connections between mother-infant sleep proximity and breastfeeding. However, some Euro-American research indicates that bedsharing can coincide with family strain and stress. Here, U.S. fathers who routinely roomshared or bedshared, respectively, reported stronger bonds to their babies than solitary sleeping fathers, but bedsharing fathers also reported more negative infant temperament.

Population-Based Survey Showing That Breastfed Babies Have a Lower Frequency of Risk Factors for Sudden Infant Death Syndrome Than Nonbreastfed Babies

Justification: Breastfeeding provides the best infant food, and closeness to the mother is crucial for successful breastfeeding. However, sharing parents' beds and sleeping on the stomach poses a high risk for sudden infant death syndrome (SIDS). There is little information on these practices regarding the Spanish population. Objective: To explore breastfeeding and bed-sharing practices in the study population Materials and Methods: A cross sectional observational study was conducted through an anonymous telephone survey with a representative random sample of babies born in the Health Area of La Marina Baixa, Alicante, between 2018 and 2019. A previous-day strategy was implemented to determine the feeding and bed-sharing variables. Results: The total breastfeeding and formula-feeding rates were 47.0% and 52.9%, respectively. The overall bed-sharing rate was 66.5%. The breastfeeding rate was 86.4% with bed-sharing and 13.6% without bed-sharing. The rate of prone sleeping position in children younger than 6 months of age was 9.3-3.5% with breastfeeding and 5.8% with formula feeding. Lower frequencies of tobacco, alcohol, and nonsupine sleeping positions were observed among mothers who practiced breastfeeding and bed-sharing. Conclusions: We found a close relationship between breastfeeding and bed-sharing and a lower frequency of SIDS risk factors associated with both practices. Families should be informed about the risk factors associated with SIDS to encourage safe bed-sharing while avoiding recommendations that discourage breastfeeding.

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.

Overview of clinical trial protocols for behavioral insomnia in infants

OBJECTIVE

to describe the overview of clinical trial protocols for behavioral insomnia in infants.

METHODS

an analytical study that reviewed protocols registered with the International Clinical Trials Registry Platform between August and September 2019, aiming to identify the interventions for behavioral insomnia in infants, the comparators, the main primary, secondary outcomes and their respective measurements.

RESULTS

eleven protocols registered between 2004 and 2018 were included. Nurses were the main coordinators of protocols (45.5%), with proposals using educational technologies, one-to-one and online follow-up consultations. The main outcome was improvement of infant and maternal sleep patterns. Secondary outcomes were anxiety, depression, and parental sexual satisfaction. To measure them, the following were used: sleep diary (54.5%), actigraphy (45.4%), and the Pittsburgh Sleep Quality Interview (36.3%) and Extended Brief Infant Sleep Questionnaire (27.2%) were used.

CONCLUSION

the protocols proposed interventions for independent sleep, aiming at quality of sleep for the whole family.

The impact of co-sleeping less than 6 months on children's anxiety, oral habits, and malocclusion in a Spanish sample between 2 and 5 years old: a cross-sectional study

OBJECTIVES

Families often use co-sleeping to mitigate potential physiological and emotional effects on infants. The purpose of this study was to investigate whether the early termination of co-sleeping is associated with high levels of anxiety, non-nutritive sucking habits for self-comfort, and increased malocclusion.

METHODS

A cross-sectional study was performed on the parents of 215 children [aged 2-5 years (3.94 ± 0.89)], who were divided according to the duration of co-sleeping (≤6 months or >6 months). The parents completed a questionnaire about co-sleeping, sucking, breastfeeding habits, and anxiety. Finally, a clinical examination was carried out to diagnose malocclusion according to the World Health Organization (WHO) index, and the aesthetic component of the Index of Orthodontic Treatment Need (IOTN-AC) was recorded.

RESULTS

Children that co-slept for 6 months or less had an increased incidence of pacifier use (P < 0.05), finger sucking (P < 0.01), and atypical swallowing (P < 0.05). Lower anxiety levels were found in the group with a longer duration of co-sleeping (P < 0.01). In the assessment of malocclusions, the group that co-slept for ≤6 months had higher IOTN scores (P < 0.01) and WHO indices (P < 0.05); in addition, there were differences in anterior open bite (P < 0.05), posterior crossbite (P < 0.01), skeletal Class II (P < 0.01), canine Class II (P < 0.05), and overjet (P < 0.05).

CONCLUSION

A co-sleeping duration of >6 months appears to be a protective factor associated with less anxiety, fewer negative sucking habits, and a decreased incidence of malocclusions in co-sleeping children.

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.

Revisiting the roots of attachment: A review of the biological and psychological effects of maternal skin-to-skin contact and carrying of full-term infants

During the early period of hypothesis building and empirical testing of attachment theory, a major emphasis was placed on mother-infant physical contact. In spite of this, mother-infant contact has received scant attention amongst attachment and child development researchers in the past decades. Here, a brief theoretical framework for mother-infant contact is presented, drawing on animal studies as well as human studies of preterm infants and neonates. Salient mechanisms may include an extended sensitive period during early infancy, requiring specific somatosensory stimuli for bio-behavioral homeorhesis; oxytocinergic and epigenetic pathways; kinesthetic stimuli and face-to-face proximity allowing for increased social interaction. Studies of extended human mother-full-term infant physical contact have demonstrated positive effects in multiple domains. For infants, these include sleep organization, temperature and heart rate regulation, behavioral response, crying/colic, socio-emotional development, attachment quality, speech development opportunities and mother-child interactions. For mothers, studies demonstrate improved depressive symptomatology, physiological stress regulation, contingent responsivity, breastfeeding and mother-child interactions. Parent-infant attachment quality has gained prominence as a trauma-resilience factor as well as a predictor of adult physical health. The potential role of mother-infant contact as an attachment promoting intervention as well as future research subjects are discussed. Current evidence supports the original attachment research that early maternal touch provision may influence infant socio-emotional development and attachment quality, with positive implications for mother-child relationship functioning.