Discrepancies in maternal reports of infant sleep vs. actigraphy by mode of feeding

Early sleep intervention for improving infant sleep quality: a randomized controlled trial, preliminary result

BACKGROUND

Healthy sleep issues should provide to family within first 6 months of infant's life. This study aimed to evaluate the effect of early sleep intervention on nighttime sleep quality.

METHODS

Eligible infants aged 4 months ± 2 weeks were randomized to receive early sleep intervention or usual care. Data on sleep variables were obtained via parental interview at baseline and 6 months of age. Using logistic regression to analyze the efficacy of early sleep intervention.

RESULTS

At baseline, 335 eligible infants were enrolled and randomized. In total, 306 participants were final analyzed: early sleep intervention group (n = 148) and the usual care group (n = 158). The early sleep intervention group had a significantly longer nighttime sleep duration and a shorter night waking duration than the usual care group (585.20 ± 80.38 min vs. 496.14 ± 87.78 min, p < .001 and 61.01 ± 36.38 min vs. 89.72 ± 45.54 min, p < .001). At 6 months of age, the early sleep intervention group had a longer night sleep duration (≥ 4 h/time) than the usual care group (adjusted odds ratio: 2.39, 95% confidence interval: 1.34-4.28).

CONCLUSIONS

Early sleep intervention should be recommended to infants at 4 months of age as a part of well childcare to improve infant sleep quality.

TRIAL REGISTRATION

Thai Clinical Trials Registry (thaiclinicaltrial.org). Retrospective registered TCTR20230117001 (17/01/2023).

The effects of massage therapy and white noise application on premature infants' sleep

AIM

Sleep is vital to premature infants' physical, social and emotional development. The significance of sleep duration, efficiency, and function in premature infants regarding growth development, behavior and neurological development has been increasing.

MATERIALS AND METHODS

This study was conducted in a randomized controlled experimental design with three groups. Premature infants at 28-37 weeks of gestation who were admitted to the Neonatal Intensive Care Unit of Şanlıurfa Mehmet Akif İnan Training and Research Hospital Haliliye Annex Building were the research population. The sample of the present study consisted of 120 premature infants in the massage therapy group (40), white noise group (40), and control group (40).

RESULTS

The sleep duration and sleep efficiency of the premature infants in the massage group increased compared to before the application, whereas the number of awakenings and WASO values decreased. The sleep duration of premature infants in the massaged group increased by some five hours. In the white noise group, the sleep duration increased by about two hours than the pre-treatment, and there was an increase in sleep efficiency. White noise application provided a significant decrease in the number of awakenings and WASO values in premature infants.

CONCLUSION

In this experimental study, which was designed with three groups, it was revealed that massage and white noise application in premature infants were significant non-pharmacological methods to increase sleep duration and sleep efficiency. It was concluded that massage therapy and white noise application is one of the considerable interventions regarding sleep duration, efficiency and functions in premature infants who left the intrauterine period early.

Does the feeding method affect the quality of infant and maternal sleep? A systematic review

Breastfeeding brings many benefits to both mother and infant. Although, many women stop breastfeeding their infants too soon. The perceived association between breastfeeding and sleep may influence their decision to terminate breastfeeding. In our systematic review, we focused on mapping the relationship between infant feeding method and total sleep time (TST), number of nocturnal awakenings, awakenings after sleep onset (WASO) of mothers and infants and sleep quality of mothers. We searched four databases according to selected keywords and inclusion criteria - articles published in peer-reviewed journals between 2012 and 2022; English language; a sample consisting of mothers, infants, or both (without psychiatric and health problems); a comparison of the sleep quality of breastfed and formula-fed children or breastfeeding and formula-fed mothers. We read 260 full texts of selected articles. A total of 35 articles were included in this review. Due to significant heterogeneity, meta-analysis was not possible to accomplish. The results are processed according to narrative synthesis. Most studies agree that breastfed infants wake up more often at night. Total sleep time and time spent awake during the night (WASO) did not differ between breastfed and non-breastfed infants. We observed identical results in sleep variables among mothers. Additionally, there was no difference in maternal sleep quality. The synthesis revealed that the results may have differed due to using subjective, objective methods or the infant's age. It is important to remember that night waking is a more complex concept. Infants wake for many reasons, not just due to breastfeeding. The narrative synthesis indicated that the chosen study design, measurement method, the variables, and the infant's age could influence outcomes. In addition, other variables appeared that may affect the entire process. Therefore, we recommend that attention be paid to this in future studies.

The Relationship Between Maternal and Infant Sleep Duration Across the First Two Years

OBJECTIVES

The first objective of this study was to determine how mother-infant sleep duration is related across the first 2 years of life. The second objective was to determine whether these relationships change across the first 2 years of life. The third objective was to understand demographic and health predictors of the relationship between maternal and child sleep.

METHODS

Parents of 464 infants from the STRONG Kids 2 study reported their own and infants' nocturnal sleep duration and other health information (i.e., breastfeeding) at 3, 12, 18, and 24 months postpartum.

RESULTS

Latent transition models revealed 2 mother-infant sleep profiles exist at 3 to 24 months. The low maternal sleep ( LMS ) pattern was characterized by lower maternal sleep duration than the recommended amount and lower infant sleep duration. The average maternal sleep ( AMS ) pattern was characterized by average maternal sleep duration meeting the recommended standard and average infant sleep duration. Approximately half of the mothers who started in the LMS profile transitioned to the AMS profile after 12 months postpartum. The sleep profiles stabilized after 12 months postpartum with limited transitions across 12 to 24 months. More infant-signaled nighttime wakings, later bedtimes, more infant sleep problems, and more exclusive breastfeeding were predictors of being in the LMS profile.

CONCLUSION

Mother-infant sleep profiles stabilized after age 12 months, and mother-infant sleep profiles are driven by infant sleep quality during the night. The findings suggest the need to establish a healthy sleep routine for mothers and infants in the first year of life to promote longer-term sleep hygiene.

Relationships between postpartum depression, sleep, and infant feeding in the early postpartum: An exploratory analysis

Introduction

The study objectives were to determine the relationships between postpartum depression and maternal and infant sleep parameters and to examine the impact of infant feeding method on infant and maternal sleep and postpartum depression symptomatology.

Methods

Participants were 61 new mothers aged 18 to 45 years old, and their full-term, normal birth-weight, singleton infants. Participants were recruited from a large teaching hospital in northeast England. Data collection took place in participants' homes. The study used a prospective longitudinal design, with data collected at six, 12 and 18 weeks postpartum. We collected data on total sleep time, longest sleep period, wake after sleep onset, and night waking for mothers and infants objectively from actigraphic records and subjectively from maternal sleep logs. Participants reported on sleep disturbances using the General Sleep Disturbances Scale, on maternal sleepiness, and on depression symptomatology using the Edinburgh Postnatal Depression Scale.

Results

Scores on the Edinburgh Postnatal Depression Scale and General Sleep Disturbances Scale were consistently correlated with each other (6 weeks r = 0.452, p < 0.01; 12 weeks r = 0.317, p < 0.05; 18 weeks r = 0.493, p < 0.01), and did not correlate with objective measures or subjective reports of maternal or infant sleep. Edinburgh Postnatal Depression Scale scores at six, 12 and 18 weeks were predicted by General Sleep Disturbances Scale, prior Edinburgh Postnatal Depression Scale score, or both, but not by sleep parameters. With regard to infant feeding method, EPDS score was not higher among exclusively breastfeeding than among exclusively formula-feeding participants at any time point (6 weeks  t = 0.306, p = 0.762; 12 weeks  t = 0.343, p = 0.733; 18 weeks  t = 0.426; p = 0.673). Different pathways emerged to predict Edinburgh Postnatal Depression Scale score for exclusively breastfeeding and exclusively formula-feeding women.

Discussion

Postpartum depression may be associated with disturbed sleep due to negative perception of sleep among depressed women, rather than disrupted sleep causing postpartum depression. With regard to infant feeding method, exclusively breastfeeding women are not more likely to suffer from postpartum depression, and different pathways may predict development of postpartum depression symptoms in exclusively breastfeeding and exclusively formula feeding women.

Preliminary Exploration into the Impact of Mistimed Expressed Breast Milk Feeding on Infant Sleep Outcomes, Compared to Other Feeding Patterns

Background and Objective: The presence and fluctuation of melatonin in breast milk during the night and day may be providing sleep timing information to infants, thereby supporting/enabling the development of their own circadian cycle. If this is the case, then it is important that infants consume breast milk according to the time of day it is produced. However, breast milk is not always consumed at the "right" time. The aim of this study was to investigate whether consuming mistimed expressed breast milk impacts infant sleep compared with other feeding types. Methods: A total of 329 mothers completed an online anonymous survey. Mothers were grouped into one of five groups; direct breastfed only, formula only, express mistimed, express-timed, and combined breastfed/formula fed. Results: Cross-sectional analysis showed mistimed expressed breast milk was significantly associated with delayed sleep onset of the infant (p < 0.001), but direct breastfed infants had significantly more awakenings at night (p < 0.001). Conclusions: The findings from this study suggest a potential effect of mistimed expressed breast milk consumption on an infant's circadian rhythm, affecting some aspects of their sleep. This is an important first step in exploring mistimed feeding on infant sleep outcomes and provides preliminary evidence that warrants future research.

The Effectiveness of Sleep Training: Fact or Fiction?

Introduction

In Western cultures, parents often view infant sleep as problematic. Family, friends, and doctors may advise parents to “sleep train” assuming it is safe and effective, without considering its possible side effects, including its impact on breastfeeding. Unfortunately, it may reduce night feeds and result in earlier supplementation or weaning. The larger question is whether sleep training is worth the risk (i.e., does it improve infant sleep?). Our goal was to examine the data on the effectiveness of sleep training interventions on infant/toddler sleep.

Methods

PubMed and Google Scholar were searched for specific terms to identify articles that included behavioral sleep interventions and objective measures of sleep pre-and postntervention. Two objective infant sleep measures were examined: Night wakings and total sleep duration. Articles were then reviewed for evidence of the effectiveness of these interventions to reduce night wakings and increase total sleep duration.

Results

Five articles were identified that met the criteria for inclusion. Overall, there was no evidence that sleep training improves infant sleep.

Applications for Practice

The claim that sleep training is effective in changing infant sleep is not warranted. Given the potential side effects on breastfeeding, parents should be cautioned about engaging these behavioral sleep interventions if they have breastfeeding goals they want to achieve.

Prevalence of infantile wheezing and eczema in a metropolitan city in Japan: A complete census survey

Infantile wheezing and eczema are associated with the subsequent onset of asthma and other atopic diseases. However, there are no large population-based surveys on infantile allergic symptoms in Japan. The objective of the study was to determine the prevalence of wheezing and asthma in infants in Nagoya, Japan. This population-based cross-sectional study was performed in the metropolitan city of Nagoya, Japan. We surveyed parents to ascertain the prevalence of wheezing and eczema in infants who attended group health checkups at 3, 18, and 36 months of age. Their parents completed modified questionnaires from the International Study of Asthma and Allergies in Childhood. More than 90% of the approximately 40,000 children in each study group living in the target area were included in the survey. The prevalence of wheezing was 8%, 17%, and 13% at 3, 18, and 36 months, respectively, and was characterized by birth season. The prevalence of eczema was 24%, 30%, and 31%, at 3, 18, and 36 months, respectively. Participants born in autumn and winter had a higher incidence of eczema in each age group. Three-quarters of the children had a parental history of allergic conditions. Parental allergic diseases and male gender are risk factors for wheezing and eczema in children. This survey had a high response rate and covered almost the entire population of the target age groups in a large city. We believe that the results of this study, therefore, provide a much higher level of confidence regarding the prevalence of allergies in infants in Japan than that in previous studies with limited cohorts.

Postpartum sleep health in a multiethnic cohort of women during the COVID-19 pandemic in New York City

OBJECTIVE/DESIGN

Cross-sectional study to examine the determinants of sleep health among postpartum women during the COVID-19 pandemic in New York City (NYC).

SETTING/PARTICIPANTS

A subset of participants recruited as part of the COVID-19 Mother Baby Outcomes (COMBO) cohort at Columbia University (N = 62 non-Hispanic White, N = 17 African American, N = 107 Hispanic).

MEASUREMENTS

Data on maternal sleep, COVID-19 infection during pregnancy, sociodemographic, behavioral, and psychological factors were collected via questionnaire at 4 months postpartum. Self-reported subjective sleep quality, latency, duration, efficiency, disturbances, and daytime dysfunction were examined as categorical variables (Pittsburgh Sleep Quality Index [PSQI]). Associations between sleep variables and COVID-19 status, time of the pandemic, sociodemographic, behavioral, and psychological factors were estimated via independent multivariable regressions.

RESULTS

Mothers who delivered between May-December 2020, who delivered after the NYC COVID-19 peak, experienced worse sleep latency, disturbances and global sleep health compared to those who delivered March-April 2020, the peak of the pandemic. Maternal depression, stress and COVID-19-related post-traumatic stress were associated with all sleep domains except for sleep efficiency. Maternal perception of infant's sleep as a problem was associated with worse global PSQI score, subjective sleep quality, duration, and efficiency. Compared to non-Hispanic White, Hispanic mothers reported worse global PSQI scores, sleep latency, duration and efficiency, but less daytime dysfunction.

CONCLUSIONS

These findings provide crucial information about sociodemographic, behavioral, and psychological factors contributing to sleep health in the postpartum period.

Effectiveness of behavioral sleep interventions on children's and mothers' sleep quality and maternal depression: a systematic review and meta-analysis

This systematic review and meta-analysis was conducted to investigate the effectiveness of behavioral sleep interventions (BSIs) on the number of child night awakenings, and maternal sleep quality and depression. The search followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) using PubMed, CINAHL, Cochrane, and EMBASE databases and retrieved studies published until April 2021. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for child sleep problems, and the mean differences (MD) and 95% CI for the number of child night awakenings, and maternal sleep quality and depression. Ten studies of 1628 initial searched were included in the final analysis. Two of the 10 studies were divided into two subgroups by participants and intervention type; thus, 12 subgroups were included in the meta-analysis. BSIs significantly reduced child sleep problems (OR 0.51; 95% CI 0.37–0.69) and improved maternal sleep quality (MD − 1.30; 95% CI − 1.82 to − 0.77) in the intervention group. There were no significant differences in the number of child night awakenings and maternal depression between the two groups. More RCTs to examine the effect of BSIs considering children’s age, duration of intervention, and outcome measuring time points are needed.

Infant sleep patterns and maternal postpartum fatigue: A cross-sectional study

AIM

Unpredictable nature of infant sleep-wake cycles go against that of the adult sleep. Maternal sleep quality is acknowledged as a main factor to postpartum fatigue. This study explored the effects of infant sleep patterns on maternal postpartum fatigue.

METHODS

A total of 319 mothers of infants from two teaching hospitals in the Nantong City were enrolled. Maternal fatigue status and infant sleep patterns were assessed by the Fatigue Scale (FS-14) and the Brief Infant Sleep Questionnaire (BISQ). Generalized estimating equation analyses were perform to explored the effect of infant sleep patterns on maternal fatigue.

RESULTS

Sleep-onset time later than 10 p.m., and nocturnal wakefulness more than 60 min were risk factors of postpartum fatigue. After controlling the confounding variables, infant sleep patterns were still the determinant factors of postpartum fatigue.

CONCLUSION

Infant sleep pattern is a factor of maternal postpartum fatigue. It is recommended to promote infant sleep so as to improve maternal sleep quality and finally alleviate postpartum fatigue.

The importance of sleep and parity in understanding changes in weight and breastfeeding behavior among postpartum women

BACKGROUND

Breastfeeding duration has been linked with the health of both women and their children, but research that considers women's weight change postpartum and practical factors that may impact their quality of life (i.e., sleep quantity, number of children) is limited.

METHOD

A survey was administered to 568 women (M age = 31.32 years; SD = 4.21) who had given birth within the past year. The survey included assessments of pre- and post-pregnancy weight and height, breastfeeding practices, current sleep quantity, presence of breastfeeding-specific support, and other demographics including their total number of children.

RESULTS

Greater pre-pregnancy to postpartum weight increase was related to shorter duration of breastfeeding. Mothers who exclusively breastfed for the first six months had less postpartum weight increase (i.e., the discrepancy between their pre-pregnancy and post-pregnancy weight was smaller) than those who did not. Fewer children and greater hours of sleep were significantly associated with longer duration of breastfeeding. Sleep partially accounted for the relationship between body mass index change and breastfeeding duration. Breastfeeding-specific support did not impact the effect of low sleep on shorter breastfeeding duration.

CONCLUSIONS

Duration of breastfeeding may suffer due to fatigue. Sleep plays a key role in understanding the ways in which weight change impact breastfeeding behavior. Greater holistic support for mothers in the postpartum period is needed to foster an environment that encourages 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.

Concordance between subjective and objective measures of infant sleep varies by age and maternal mood: Implications for studies of sleep and cognitive development

Infant habitual sleep has been proposed as an important moderator of development in domains such as attention, memory or temperament. To test such hypotheses, we need to know how to accurately and consistently assess habitual sleep in infancy. Common assessment methods include easy to deploy but subjective parent-report measures (diary/sleep questionnaire); or more labour-intensive but objective motor movement measures (actigraphy). Understanding the degree to which these methods provide converging insights is important, but cross-method agreement has yet to be investigated longitudinally. Moreover, it is unclear whether concordance systematically varies with infant or maternal characteristics that could represent confounders in observational studies. This longitudinal study (up to 4 study visits/participant) investigated cross-method concordance on one objective (7-day actigraphy) and three commonly used subjective (7-day sleep diary, Brief Infant Sleep Questionnaire, Sleep & Settle Questionnaire) sleep measures in 76 typically developing infants (age: 4–14 months) and assessed the impact of maternal characteristics (stress, age, education) and infant characteristics (age) on cross-method concordance. In addition, associations between objective and subjective sleep measures and a measure of general developmental status (Ages & Stages Questionnaire) were investigated. A range of equivalence analyses (tests of equivalence, correlational analyses, Bland-Altman plots) showed mixed agreement between sleep measures. Most importantly, cross-method agreement was associated with maternal stress levels and infant age. Specifically, agreement between different measures of night waking was better for mothers experiencing higher stress levels and was higher for younger than older infants; the reverse pattern was true for day sleep duration. Interestingly, objective and subjective measures did not yield the same patterns of association with developmental domains, indicating that sleep method choice can influence which associations are found between sleep and cognitive development. However, results converged across day sleep and problem-solving skills, highlighting the importance of studying day sleep in future studies. We discuss implications of sleep method choice for investigating sleep in the context of studying infant development and behaviour.

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A range of equivalence analyses showed mixed agreement between subjective and objective sleep measures.

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Cross-method agreement was associated with maternal stress levels and infant age.

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Objective and subjective measures did not yield the same patterns of association with developmental domains except for day sleep duration.

Type of Milk Feeding and Introduction to Complementary Foods in Relation to Infant Sleep: A Systematic Review

Inconsistent conclusions from infant sleep and feeding studies may influence parents feeding-related decisions. This study aimed to systematically review the existing literature on infant sleep and its relation to the timing of introduction to complementary foods and type of milk feeding to better understand their role(s) in infant sleep. Cohort, longitudinal, cross-sectional studies, and controlled trials were identified using online searches of five databases up to April 2020. Twenty-one articles with a total of 6225 infants under 12 months-of-age were eligible. Exclusively breastfed infants (≤6 months-of-age) had a greater number of night wakings, but most studies (67%) reported no difference in night-time and 24 h sleep duration compared to formula-fed infants. However, after 6 months-of-age, most studies (>65%) reported breastfed infants to sleep less in the night-time and over 24 h compared to formula-fed infants. Furthermore, studies reported no association between the timing of introduction to complementary foods and infant sleep duration (<12 months-of-age). Future studies using standardized methodologies and definitions, transdisciplinary expertise, and longitudinal design are required to better understand the complex role of feeding on sleep.

Associations between parent-reported and objectively measured sleep duration and timing in infants at age 6 months

STUDY OBJECTIVES

To compare the estimates of sleep duration and timing from survey, diary, and actigraphy in infants at age 6 months, overall and by select demographics and other factors.

METHODS

In total, 314 infants participating in the Rise & SHINE (Sleep Health in Infancy & Early Childhood study) cohort in Boston, MA, USA, wore an actigraph on their left ankle for 7 days. Parents concurrently completed a sleep diary and the expanded version of the Brief Infant Sleep Questionnaire. Concordance between parent-reported and objective sleep estimates was assessed using Bland-Altman plots, Spearman's rank correlations, intraclass correlations, and linear regression models.

RESULTS

Mean infant age was 6.4 (0.6 SD) months; 51% were female and 42% were Non-Hispanic white. Mean total sleep duration using actigraphy was 526 (67 SD) minutes per night, 143 (42 SD) minutes per day, and 460 (100 SD) minutes during the longest nighttime sleep period. Relative to actigraphy, parent-completed survey and diary overestimated total day (by 29 and 31 minutes, respectively) and night sleep duration (67 and 43 minutes, respectively) and underestimated the longest sleep (58 minutes), with the highest agreement for sleep onset and offset timing (differences < 30 minutes). There was a tendency toward greater bias among short- and long-sleeping infants. Self-reporting bias for diary-measured longest nighttime sleep and total night sleep duration was higher in infants of parents reporting a problem with their baby's night awakenings and in low-income families, respectively.

CONCLUSIONS

Our findings underscore the need to be cautious when comparing findings across studies using different sleep assessment methods.

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.

Infant feeding practices and sleep at 1 year of age in the nationwide ELFE cohort

Sleep problems reported by parents affect 20% to 30% of infants. Few studies focused on the longitudinal association between infant feeding practices and sleep, especially in France. Analyses were based on 8,696 infants from the French national birth cohort ELFE. Collection of feeding practices from birth to 10 months allowed for the identification of trajectories of use of baby cereals and thickened formula by group‐based trajectory modelling and calculation of duration of any breastfeeding (BF) and age at complementary feeding introduction (CFI) excluding baby cereals. Total sleep duration (TSD), night waking (NW) and sleep onset difficulties (SOD) were reported at age 1. Associations between feeding and sleep were tested by multinomial logistic regressions. BF duration ≥6 months was associated with parent‐reported frequent NW, SOD and TSD ≤ 12 h/24 h at age 1. For TSD and SOD, this association was no longer significant after accounting for parental sleep‐related practices. Early use of baby cereals (≤5 months) was associated with poor sleep. Early CFI (<4 months) was associated with shorter TSD and SOD but not NW. Early use of thickened formula (only <6 months) was related to poor sleep at age 1 (NW and SOD), whereas late (around 6 months) use of thickened formula was associated with better sleep. BF duration ≥6 months was related to poor sleep at age 1 but not after adjustment on 1‐year parental sleep‐related practices except for NW. The use of baby cereals or early CFI was not related to better sleep at age 1.

Time for bed! Earlier sleep onset is associated with longer nighttime sleep duration during infancy

OBJECTIVE/BACKGROUND

Clinical recommendations include putting infants to bed using a consistent bedtime routine at an appropriate hour to promote longer nighttime sleep. Actigraphy was used in this exploratory study to examine how bedtime routines and nighttime sleep onset were associated with nighttime total sleep time (TST) and efficiency from 6 to 24 weeks of age.

PATIENTS/METHODS

Infants (n = 24) wore sleep actigraphs for three, one-week periods at 6, 15, and 24 weeks of age. Nighttime TST, sleep efficiency, sleep onset and offset were quantified. Mothers reported on infant bedtime routines using the Brief Infant Sleep Questionnaire at each age. Multilevel models examined between- and within-person associations.

RESULTS

As infants aged, sleep onset was earlier, and bedtime routines became shorter (p's < 0.05). Infants fell asleep between 7 and 8:00PM on 24% of the nights. Most mothers (70%) reported that they often fed infants to sleep for the night. For every 1 h earlier in infants' usual sleep onset, nighttime TST was 34.4 min longer that night (p < 0.01). Infants with earlier than usual sleep onset had slightly earlier sleep offset the next morning (8.4 min for every 1 h earlier in onset; p = 0.02). Between-person analyses showed similar patterns. Infants with a more consistent bedtime routine and who were not typically fed to sleep at bedtime had longer nighttime TST at 6 weeks, with a trend or no association at later ages.

CONCLUSION

Infants who fell asleep earlier also slept longer at night. Keeping infants up later in hopes of them sleeping in longer may be counterproductive.

Actigraphy in sleep research with infants and young children: Current practices and future benefits of standardized reporting

Actigraphy is a cost‐efficient method to estimate sleep–wake patterns over long periods in natural settings. However, the lack of methodological standards in actigraphy research complicates the generalization of outcomes. A rapidly growing methodological diversity is visible in the field, which increasingly necessitates the detailed reporting of methodology. We address this problem and evaluate the current state of the art and recent methodological developments in actigraphy reporting with a special focus on infants and young children. Through a systematic literature search on PubMed (keywords: sleep, actigraphy, child *, preschool, children, infant), we identified 126 recent articles (published since 2012), which were classified and evaluated for reporting of actigraphy. Results show that all studies report on the number of days/nights the actigraph was worn. Reporting was good with respect to device model, placement and sleep diary, whereas reporting was worse for epoch length, algorithm, artefact identification, data loss and definition of variables. In the studies with infants only (n = 58), the majority of articles (62.1%) reported a recording of actigraphy that was continuous across 24 hr. Of these, 23 articles (63.9%) analysed the continuous 24‐hr data and merely a fifth used actigraphy to quantify daytime sleep. In comparison with an evaluation in 2012, we observed small improvements in reporting of actigraphy methodology. We propose stricter adherence to standards in reporting methodology in order to streamline actigraphy research with infants and young children, to improve comparability and to facilitate big data ventures in the sleep community.

What Is “Normal” Infant Sleep? Why We Still Do Not Know

The human need for sleep is universal and unquestioned; however, humans vary in their sleep needs according to age, individual differences, as well as cultural and social norms and practices. Therefore, what is “normal” in infant sleep and the development of sleep architecture in humans is highly dependent on biological and sociocultural variables as well as socially constructed assumptions about what infant sleep “should” look like. This paper uses a multidisciplinary approach to review papers from fields including pediatrics, anthropology, psychology, medicine, and sociology to understand “normal” infant sleep. Because human culture and behavioral practice changes much more quickly than evolved human biology, and because human evolutionary history occurred in the context of breastfeeding and cosleeping, new work in the field of infant sleep architecture development would benefit from a multidisciplinary approach. To come to a consensus about what is “normal” infant sleep, researchers must agree on underlying basic assumptions of infant sleep from which to ask question and interpret findings.