Effect of current breastfeeding on sleep patterns in infants from Asia-Pacific region

To sleep or to breastfeed: Associations between feeding method and sleep in infants and children

AIM

This study aimed to understand the association between feeding method, specifically breastfeeding versus non-breastfeeding, at 6 and 12 months and infant sleep over the first 3 years of life.

METHODS

A sample of 444 mother-infant dyads from the Maternal Adversity, Vulnerability and Neurodevelopment cohort were analysed. Based on retrospective maternal reports between 3-24 months, infants' breastfeeding status was determined at 6 and 12 months. Nocturnal sleep duration, longest period of consecutive sleep, and total sleep over 24 h were measured by maternal reports at 6, 12, 24 and 36 months.

RESULTS

Generalized Estimating Equations revealed no significant association between feeding status, both at 6 and 12 months, and nocturnal sleep duration or total sleep over 24 h between 6-36 months (p > 0.05). However, breastfeeding at both 6 and 12 months was associated with shorter periods of consecutive sleep, at 6 and 12 months (p < 0.05) but not at 24 and 36 months (p > 0.05).

CONCLUSION

Our findings suggest that breastfeeding seems to be associated with more infant sleep fragmentation but not with total sleep duration in early infancy. However, this sleep fragmentation does not persist into later infancy and early toddlerhood.

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).

Breastfeeding and Sleeping Patterns Among 6-12-Month-Old Infants in Norway

BACKGROUND

Parental behavior and infant sleep patterns can vary widely both within and between cultures and settings. Breastfeeding during the second half-year of infancy has been associated with frequent night waking, which is perceived as sleep problem among the Western societies. An understanding of sleeping patterns among breastfed infants during the second half-year of infancy is important in supporting continued breastfeeding.

OBJECTIVES

The study aimed to investigate the sleeping patterns among breastfed infants during second half-year of infancy.

METHODS

This is a cross-sectional study. Three hundred and forty-two mothers of 6-12 months old breastfed infants completed the questionnaires on socio-demographic factors, breastfeeding practices, and infant sleeping patterns, which were assessed by using the Brief Infant Sleep Questionnaire (BISQ). The Cox regression model was used to assess the factors that were associated with night sleep duration whereas demographic factors and breastfeeding practices that were associated with night waking frequency were investigated using the Poisson regression model.

RESULTS

On average, the breastfed infants slept for 11 h during the night and most infants were reported to have night waking (96.8%) and were breastfed at least once at night (93.5%). In the adjusted analyses, infants in the age group 9-12 months were less likely to sleep longer compared to infants in the 6-8 months age group [HR 1.52 95% CI (1.17, 1.98)]. A one-hour increase in daytime sleep and in night wakefulness increased the likelihood of waking up at night by 19% and 24%, respectively. Infants who had been vaccinated within the last 7 days and infants who were breastfed to sleep were more likely to have a shorter nighttime sleep duration. Nighttime breastfeeding frequency was significantly associated with a 17% increase in the likelihood of night waking [IRR 1.17 95% CI (1.13, 1.22)]. Infants who slept on their parents' bed were 1.28 times more likely to wake up at night compared to infants who slept in a separate room [IRR 1.28 95% CI (1.05, 1.59)]. Infants of parents who reported that their infants' sleep was not a problem were 34% less likely to wake up compared to infants of parents who reported that their infants' sleep was a problem [IRR 0.66 95% CI (0.49, 0.87)]. CONCLUSIONS FOR PRACTICE: Frequent night waking, bed sharing and night breastfeeding were common among 6-12 months old breastfed infants. Frequent night breastfeeding may lengthen an infant's nighttime sleep duration. The study findings indicate that adequate information and support should be given to breastfeeding mothers in relation to the sleeping pattern of breastfed infants in order to promote continued breastfeeding practices.

Childhood sleep: assessments, risk factors, and potential mechanisms

BACKGROUND

Sleep problem is a highly prevalent health issue among pediatric populations across the world. In this review, we aimed to identify risk factors contributing to sleep deficiency and poor sleep hygiene in children. Potential biological, psychosocial, and environmental mechanisms as well as research gaps in the literature are also discussed.

DATA SOURCES

A comprehensive search for relevant English language full-text, peer-reviewed publications was performed focusing on pediatric sleep studies from prenatal to childhood and adolescence in a variety of indexes in PubMed, SCOPUS, and Psych Info. Both relevant data based and systematic reviews are included.

RESULTS

This paper summarizes many risk factors for childhood sleep problems, including biological (e.g., genetics, gender, age and puberty, prenatal factors, postnatal factors); nutritional (e.g., macronutrients, micronutrients, omega-3 fatty acids, obesity); environmental (e.g., heavy metals, noise, light, air pollution); interpersonal (e.g., family, exposure to violence, screen media use, physical injury); and community/socioeconomic variables (e.g., racial/ethnicity and cultural factors, neighborhood conditions and socioeconomic status, school factors, public health disasters/emergencies), to better understand the development of sleep problems in children.

CONCLUSIONS

Poor childhood sleep is a multifactorial issue affected by a wide range of prenatal and early-life biological, environmental, and psychosocial risk factors and contributors. A better understanding of these risk factors and their mechanisms is an important first step to develop future research and prevention programs focusing on pediatric sleep problems.

The Impact of Maternity and Working Demands in Women's Sleep Pattern

This literature review seeks to understand how motherhood and profession affect women's sleep. After the birth of a child, there is an increase in dissatisfaction with the quantity and quality of sleep. Awakenings and sleep disturbances are more frequent and can lead to increased fatigue and stress to reconcile household activities and work demands. These changes in sleep can lead to physical and/or psychological health problems. Sleep hygiene and social support become fundamental for the performance of the maternal tasks, reducing risks and increasing prevention of future problems, both for women and children.

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.

Association of Breastfeeding Practices During the First 3 Months with Infant Sleep Trajectories: A Prospective Cohort Study

BACKGROUND

Breastfeeding has numerous effects on maternal and child health. The effect of breastfeeding on infant sleep remains inconclusive.

OBJECTIVES

We aimed to examine whether full breastfeeding (FBF) during the first 3 mo is associated with longitudinal infant sleep trajectories in their first 2 y of life.

METHODS

The study was embedded in the Tongji Maternal and Child Health Cohort study. Information on infant feeding practices was collected at 3 mo of age, and maternal/child pairs were assigned to the FBF or the non-FBF group (including partially breastfeeding and exclusive formula feeding) on the basis of feeding practices during the first 3 mo of life. Sleep data of infants were obtained at 3, 6, 12, and 24 mo. Total, night, and day sleep trajectories across 3 to 24 mo were estimated with group-based models. Each sleep trajectory was differentiated on the basis of sleep duration at 3 mo (long/moderate/short) and the interval from 6 to 24 mo (moderate/short). Multinomial logistic regression was used to investigate the association of breastfeeding practices with infant sleep trajectories.

RESULTS

Among the 4056 infants studied, 2558 (63.1%) received FBF for 3 mo. When compared with FBF infants, non-FBF infants had shorter sleep duration at 3, 6, and 12 mo (P < 0.01). Non-FBF infants were more likely to experience Moderate-Short (OR: 1.31; 95% CI: 1.06, 1.61) and Short-Short (OR: 1.56; 95% CI: 1.12, 2.16) total sleep trajectories and more likely to experience Moderate-Short (OR: 1.84; 95% CI: 1.22, 2.77), and Short-Moderate (OR: 1.40; 95% CI: 1.06, 1.85) night sleep trajectories than FBF infants.

CONCLUSIONS

Full breastfeeding for ≥3 mo were positively associated with longer infant sleep duration. Infants fully breastfed were more likely to experience better sleep trajectories characterized by longer duration in their first 2 y of life. Full breastfeeding may benefit infants through healthy sleep.

The Architecture of Early Childhood Sleep Over the First Two Years

INTRODUCTION

The architecture and function of sleep during infancy and early childhood has not been fully described in the scientific literature. The impact of early sleep disruption on cognitive and physical development is also under-studied. The aim of this review was to investigate early childhood sleep development over the first two years and its association with neurodevelopment.

METHODS

This review was conducted according to the 2009 PRISMA guidelines. Four databases (OVID Medline, Pubmed, CINAHL, and Web of Science) were searched according to predefined search terms.

RESULTS

Ninety-three studies with approximately 90,000 subjects from demographically diverse backgrounds were included in this review. Sleep is the predominant state at birth. There is an increase in NREM and a decrease in REM sleep during the first two years. Changes in sleep architecture occur in tandem with development. There are more studies exploring sleep and early infancy compared to mid and late infancy and early childhood.

DISCUSSION

Sleep is critical for memory, learning, and socio-emotional development. Future longitudinal studies in infants and young children should focus on sleep architecture at each month of life to establish the emergence of key characteristics, especially from 7-24 months of age, during periods of rapid neurodevelopmental progress.

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.

The relationship between diet and sleep in 2-y-old children: Results from Growing Up in New Zealand

OBJECTIVES

This study aimed to examine the relationship between dietary practices and sleep in young children.

METHODS

In this study, 2-y-old children (n = 6327) and their mothers were enrolled at birth and during pregnancy, respectively. The study obtained maternal demographic, health, and lifestyle data during late pregnancy. Parents reported the 2-y-old child's dietary practices on a food frequency questionnaire, as well as sleep duration and night-waking frequency. Measures of dietary intake quantified servings per day for each food group (grouped as low/moderate/high intake). Sleep measures were as inadequate sleep when <11 h sleep in a 24-h period and increased night waking when waking ≥2 times per night. Multivariable logistic regression analyses examined associations between toddler diet and sleep, which were described using adjusted odds ratios (ORs) and 95% confidence intervals.

RESULTS

In this study, 2-y-old children (n = 6288) slept for a mean of 12.3 hours (standard deviation: ±1.5 hours) over a 24-h period, with 734 children (12%) getting <11 h of sleep in 24 h. Increased night waking occurred in 1063 children (17%). Compared with low intake, high soft drink/snack/fast food intake was associated with inadequate sleep (OR: 1.37) and increased night waking (OR: 1.34). High milk/cheese/yoghurt intake (OR: 1.55) was associated with increased odds of night waking, but moderate (OR: 0.81) or high (OR: 0.78) vegetable intake was associated with decreased odds of night waking. Exposure to screens (OR: 1.28) and heavy maternal cigarette smoking (OR: 2.20) were also associated with inadequate sleep and increased night waking, respectively.

CONCLUSIONS

At age 2 y, higher consumption of soft drinks/snacks/fast foods is associated with shorter, more disrupted sleep. Conversely, higher vegetable consumption is associated with less disrupted sleep. Dietary modifications may improve toddlers' sleep.

Association between breastfeeding and sleep patterns in infants and preschool children

BACKGROUND

Although most studies have reported unfavorable short-term effects of breastfeeding on early-childhood sleep-wake behaviors that potentially attenuate over time, findings have remained inconsistent.

OBJECTIVES

We assessed associations of breastfeeding with longitudinal day-, night-, and total-sleep trajectories and with sleep-wake behaviors in healthy infants and preschoolers.

METHODS

Caregivers of naturally conceived, term, singleton infants (n = 654) completed the Brief Infant Sleep Questionnaire (3, 6, 9, 12, 18, and 24 mo) and/or Children's Sleep Habits Questionnaire (54 mo), and provided information on their infants' breastfeeding status at 3 mo. Trajectory analyses derived 4 day- (n = 243), 3 night- (n = 248), and/or 4 total- (n = 241) sleep trajectories, each differing in length of sleep duration (short/moderate/long) and variability (variable/consistent). Sleep-wake behaviors from 3 to 24 mo (day/night/total-sleep durations and duration/number of night awakenings) were also assessed for associations with breastfeeding.

RESULTS

After adjusting for potential covariates, formula-fed infants, relative to fully breastfed (predominant or exclusive) infants, were significantly less likely to exhibit moderate (OR: 0.28; 95% CI: 0.11, 0.70) and long consistent (OR: 0.18; 95% CI: 0.07, 0.50) night-sleep trajectories and less likely to exhibit moderate (OR: 0.21; 95% CI: 0.07, 0.61) and long consistent (OR: 0.12; 95% CI: 0.04, 0.38) and long variable (OR: 0.16; 95% CI: 0.05, 0.56) total-sleep trajectories, instead of short variable night- and total-sleep trajectories. Partially breastfed infants did not differ from fully breastfed infants for both night- and total-sleep trajectories. No significant differences were found between all groups for day-sleep trajectories. Fully breastfed infants had longer night- (6, 9, 12, and 24 mo) and total- (3 and 12 mo) sleep durations than formula-fed infants, albeit a greater number of night awakenings (from 6 to 12 mo).

CONCLUSIONS

Despite more night awakenings, fully breastfed infants have overall longer night- and total-sleep durations (sleep trajectories) than formula-fed infants.

Classification of psychiatric symptoms using deep interaction networks: the CASPIAN-IV study

Identifying the possible factors of psychiatric symptoms among children can reduce the risk of adverse psychosocial outcomes in adulthood. We designed a classification tool to examine the association between modifiable risk factors and psychiatric symptoms, defined based on the Persian version of the WHO-GSHS questionnaire in a developing country. Ten thousand three hundred fifty students, aged 6–18 years from all Iran provinces, participated in this study. We used feature discretization and encoding, stability selection, and regularized group method of data handling (GMDH) to classify the a priori specific factors (e.g., demographic, sleeping-time, life satisfaction, and birth-weight) to psychiatric symptoms. Self-rated health was the most critical feature. The selected modifiable factors were eating breakfast, screentime, salty snack for depression symptom, physical activity, salty snack for worriedness symptom, (abdominal) obesity, sweetened beverage, and sleep-hour for mild-to-moderate emotional symptoms. The area under the ROC curve of the GMDH was 0.75 (CI 95% 0.73–0.76) for the analyzed psychiatric symptoms using threefold cross-validation. It significantly outperformed the state-of-the-art (adjusted p < 0.05; McNemar's test). In this study, the association of psychiatric risk factors and the importance of modifiable nutrition and lifestyle factors were emphasized. However, as a cross-sectional study, no causality can be inferred.

Correlates of Sleep Duration in Early Childhood: A Systematic Review

OBJECTIVE

This systematic review aimed to summarize correlates of sleep duration in children under 5 years of age.

METHODS

Six electronic databases (PubMed, PsycINFO, MEDLINE, CINAHL, SPORTDiscus, and Scopus) were searched from inception to May 2019. Observational studies and intervention studies reporting cross-sectional results from baseline data were considered. Data were extracted using a predesigned form and potential correlates were categorized following a sociological framework.

RESULTS

One-hundred and sixteen studies, representing 329,166 children, met the inclusion criteria, with a high risk of bias in 62 included studies. A total of 83 correlates of sleep duration were identified. Among the associations studied four or more times, correlates of nap duration were child's age and nighttime sleep onset/bedtime; correlates of nighttime sleep duration were household income, parent marital status, parental adiposity level, nighttime sleep duration at younger age, nighttime sleep onset/bedtime, nighttime sleep wakeup time, and frequency of current bedtime routine; correlate of total sleep duration was screen time.

CONCLUSIONS

Young children from low-income households, single families, or having overweight parents may be at risk for short sleep duration. Promoting healthy sleep duration from an early age appears essential. Effective practices may include encouraging an earlier bedtime, limiting screen time, and establishing a regular bedtime routine. The absence of consistent evidence in the psychological, cognitive, and emotional domain as well as the physical environmental domain warrants further research.

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.

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.

What does sleep hygiene have to offer children's sleep problems?

Sleep hygiene practices have been described extensively in the literature. There is considerably less clarity about relationships between particular elements of sleep hygiene and particular sleep outcomes, and which intervention approaches using sleep hygiene principles are effective. In this review, we describe themes extracted from a systematic review of the sleep hygiene literature. We systematically searched Psycinfo, CINAHL, Cochrane, Ovid Medline, Embase, and Web of Science Search Engines up to August, 2017. We included all studies that associated sleep hygiene (behaviors adjacent to bedtime and during the night) with sleep duration and/or sleep onset latency and/or night waking or that used sleep-hygiene based interventions to improve sleep duration and/or sleep onset latency and/or night waking (n = 44). We organized our findings into themes by age group, sleep hygiene factors, and interventions. We provide evidence-based recommendations about areas of sleep hygiene that have significant empirical support and those that require urgent attention.

Uninterrupted Infant Sleep, Development, and Maternal Mood

OBJECTIVES

Contrary to the importance of total sleep duration, the association between sleeping through the night and development in early infancy remains unclear. Our aims were to investigate the proportion of infants who sleep through the night (6- or 8-hour sleep blocks) at ages 6 and 12 months in a longitudinal cohort and to explore associations between sleeping through the night, mental and psychomotor development, maternal mood, and breastfeeding.

METHODS

At 6 and 12 months of age, maternal reports were used to assess the longest period of uninterrupted infant sleep and feeding method (n = 388). Two different criteria were used to determine if infants slept through the night: 6 and 8 hours of uninterrupted sleep. Mental and psychomotor developmental indices (Bayley Scales of Infant Development II) and maternal mood (Center for Epidemiologic Studies Depression Scale) were measured at 6, 12, and 36 months of age.

RESULTS

Using a definition of either 6 or 8 hours of uninterrupted sleep, we found that 27.9% to 57.0% of 6- and 12-month-old infants did not sleep through the night. Linear regressions revealed no significant associations between sleeping through the night and concurrent or later mental development, psychomotor development, or maternal mood (P > .05). However, sleeping through the night was associated with a much lower rate of breastfeeding (P < .0001).

CONCLUSIONS

Considering that high proportions of infants did not sleep through the night and that no associations were found between uninterrupted sleep, mental or psychomotor development, and maternal mood, expectations for early sleep consolidation could be moderated.

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

OBJECTIVES

Many studies of infant sleep rely solely on parentally-reported data, assuming that parents accurately report their infant's sleep parameters. The objective of this paper is to examine whether night-time sleep parameters of exclusively breastfed or exclusively formula-fed infants differ, and whether correspondence between parental reports and objective measures varies by feeding type.

METHODS

Mother-infant dyads intending to breastfeed or formula-feed exclusively for 18 weeks were recruited. Mothers were multiparas and primiparas, aged between 18 and 45 years. Infants were full-term, normal birthweight singletons. Maternal report and actigraphic data on infant sleep were collected fortnightly, from four to 18 weeks postpartum. Data were analysed cross-sectionally using t-tests and GLM analysis to control for interaction between feed-type and sleep location.

RESULTS

Actigraphy-assessed infant sleep parameters did not vary by feed-type but parentally reported sleep parameters did. Maternal report and actigraphy data diverged at 10 weeks postpartum and discrepancies were associated with infant feeding type. Compared to actigraphy, maternal reports by formula-feeding mothers (controlling for infant sleep location) over-estimated infant's Total Sleep Time (TST) at 10 weeks and Longest Sleep Period (LSP) at 10, 12 and 18 weeks.

CONCLUSIONS

These results raise questions about the outcomes of previous infant sleep studies where accuracy of parentally-reported infant sleep data is assumed. That parental reports of infant sleep vary by feeding type is particularly important for reconsidering previous studies of infant sleep development and intervention studies designed to influence sleep outcomes, especially where feed-type was heterogeneous, but was not considered as an independent variable.

A Community-Based Study of Sleep and Cognitive Development in Infants and Toddlers

STUDY OBJECTIVES

To examine the prevalence and correlates of nighttime awakenings and to explore the association between sleep and cognitive development in a community sample of infants and toddlers.

METHODS

A total of 590 healthy infants (aged 2-11 months) and 512 toddlers (aged 12-30 months) from 8 provinces of China were assessed for their sleep and cognitive development. Data on sleep duration and nighttime awakenings were collected through the Brief Infant Sleep Questionnaire. Cognitive development was assessed by trained pediatricians using the Bayley Scales of Infant Development.

RESULTS

Prevalence of no nighttime awakening, and nighttime awakening(s) for 1×/night, 2×/night, and ≥ 3×/night was 6.8%, 20.2%, 33.2%, and 39.3% in infants, and was 25.8%, 34.6%, 23.8%, and 15.8% in toddlers, respectively. Nighttime awakenings were generally associated with younger age, lower maternal education level, and being currently breastfed. In addition, nighttime awakenings were associated with being boys in toddlers. After controlling for potential confounders, infants with nighttime awakenings for 2×/night were found to have significantly higher Mental Development Index (MDI) score, as compared to those without and those with more frequent nighttime awakenings. However, toddlers with nighttime awakenings for ≥ 3×/night had significantly lower MDI, as compared to those with fewer nighttime awakenings. Total sleep duration was not associated with any developmental indices in both infants and toddlers.

CONCLUSIONS

Frequent nighttime awakenings are associated with poor cognitive functions in toddlers. Meanwhile, a nonlinear association between nighttime awakenings and cognitive performance was found among infants. The findings provide a developmental context for the effect of sleep on cognitive abilities in young children. Further longitudinal studies and interventional studies on the effects of parent-based sleep-focused intervention on cognitive abilities among young children are warranted.

[Adaptation and study of the measurement properties of a sleep questionnaire for infants and pre-school children]

INTRODUCTION

Although sleep disturbances in infants and toddlers are common, there is no suitable validated tool in Spanish to evaluate sleep disorders. The Brief Infant Sleep Questionnaire (BISQ) is a well-established multidimensional questionnaire widely used internationally.

OBJECTIVES

To adapt the BISQ questionnaire to Spanish and analyse its reliability and validity. To explore its feasibility, both in the clinical context, and in epidemiological research.

METHODS

Participants were parents of children between 3 and 30 months of age. The adaptation to Spanish (BISQ-E) was achieved by using both back translation and consensus, following the international guidelines.Reliability was determined by means of test-retest and measurement of agreement (Kappa value) between 2forms of administration of the questionnaire (self-administration and clinical interview). Construct validity was established by analysing its correlation with a sleep diary.

RESULTS

A total of 87 families/children participated. The test-retest reliability undertaken in 60 subjects was excellent; r = 0.848 (P<0.001). The kappa value was 0.939 (95% CI: 0.858-1.00, P<0.001).The agreement between BISQ-E and the sleep diary was analysed in 27 families/children, with statistically significant values being obtained for the following variables: bedtime (r = 0.731), hours of night sleep (r = 0.726), hours of daytime sleep (r = 0.867), and number of nocturnal awakenings (r = 0.888) (P < 0.001).

CONCLUSIONS

The Spanish adaptation of the BISQ shows overall adequate validity and reliability for the evaluation of sleep in infants and pre-school children. Its use as a clinical tool, or for clinical-epidemiological research studies, is feasible.

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.

Sleep location and parent-perceived sleep outcomes in older infants

OBJECTIVES

Initial studies indicate more independent and consolidated sleep in the first few months in infants who sleep separately. Little is known, however, about the relationship of sleep location (separate room, room-sharing, bed-sharing) with sleep outcomes in older infants (ages 6-12 months). It was expected that those who sleep in a separate room would have better parent-perceived sleep outcomes and more positive sleep health behaviors.

METHODS

Parents of 6236 infants (6-12 months) in the United States (US) and 3798 in an international sample (Australia, Brazil, Canada, Great Britain, and New Zealand) completed a smartphone app-based expanded version of the validated Brief Infant Sleep Questionnaire.

RESULTS

A total of 37.2% of the infants in the US and 48.4% in the international sample slept in a separate room. In both samples, infants who slept in a separate room as opposed to room-sharing or bed-sharing had parent-perceived sleep outcomes and sleep-related behaviors that reflected earlier bedtimes, shorter time to fall asleep, more nighttime and total sleep, and increased sleep consolidation. They were also more likely to have a consistent bedtime routine and to fall asleep independently, as well as less likely to feed to sleep at bedtime and during the night. In addition, parents of separate room sleepers perceived bedtime to be less difficult and sleep to be better overall.

CONCLUSIONS

Overall, 6- to 12-month-old infants who slept in a separate room had better reported sleep outcomes and fewer parent-perceived disturbances at bedtime than infants who room-shared with their parents, as well compared to those who slept in their parents' bed.

Exclusive breastfeeding at three months and infant sleep-wake behaviors at two weeks, three and six months

This study assessed infant sleep-wake behavior at two weeks, three and six months as function of feeding method at three months (exclusively breastfed, partially breastfed, and exclusively formula fed infants). Mothers of 163 first-born, full-term, normal birth weight, healthy infants completed socio-demographic, depression, anxiety, and infant sleep-wake behavior measures. No effects were found for sleep arrangements, depression or anxiety, on feeding methods and sleep-wake behavior at three months. At two weeks exclusively breastfed infants at three months spent more hours sleeping and less hours awake during the 24-h period than partially breastfed infants. At three months, exclusively breastfed infants had a shorter of the longest sleep period at night than exclusively formula fed infants. At six months, exclusively breastfed infants at three months spent more hours awake at night than partially breastfed infants, awake more at night than exclusively formula fed infants, and had a shorter sleep period at night than partially breastfed and exclusively formula fed infants. This study showed differences in sleep-wake behaviors at two weeks, three and six months, when exclusively breastfed infants are compared with partially breastfed and exclusively formula fed infants at three months, while no effects were found for sleep arrangements, depression or anxiety.

Feeding methods, sleep arrangement, and infant sleep patterns: a Chinese population-based study

BACKGROUND

Findings from prior research into the effect of feeding methods on infant sleep are inconsistent. The objectives of this study were to examine infants' sleep patterns by feeding methods and sleep arrangement from birth to eight months old.

METHODS

This longitudinal cohort study enrolled 524 pregnant women at 34-41 weeks of gestation and their infants after delivery in 2006 and followed up until eight months postpartum. The study subjects were recruited from nine women and children hospitals in nine cities in China (Beijing, Chongqing, Wuhan, Changsha, Nanning, Xiamen, Xi'an, Jinan, and Hailin). Participating infants were followed up weekly during the first month and monthly from the second to the eighth month after birth. Twenty-four hour sleep diaries recording infants' sleeping and feeding methods were administered based on caregiver's self-report. Multivariable mixed growth curve models were fitted to estimate the effects of feeding methods and sleep arrangement on infants' sleep patterns over time, controlling for maternal and paternal age, maternal and paternal education level, household income, supplementation of complementary food, and infant birth weight and length.

RESULTS

Exclusively formula fed infants had the greatest sleep percentage/24 h, followed by exclusively breast milk fed infants and partially breast milk fed infants (P<0.01). Night waking followed a similar pattern. However, the differences in sleep percentage and night waking frequency between exclusively formula and exclusively breast milk fed infants weakened over time as infants developed. In addition, compared to infants with bed-sharing sleep arrangement, those with room sharing sleep arrangement had greater daytime and 24-hour infant sleep percentage, whereas those with sleeping alone sleep arrangement had greater nighttime sleep percentage.

CONCLUSIONS

Our data based on caregiver's self-report suggested that partial breastfeeding and bed-sharing may be associated with less sleep in infants. Health care professionals need to work with parents of newborns to develop coping strategies that will help prevent early weaning of breastfeeding.

A randomized controlled trial of an intervention for infants' behavioral sleep problems

Background

Infant behavioral sleep problems are common, with potential negative consequences. We conducted a randomized controlled trial to assess effects of a sleep intervention comprising a two-hour group teaching session and four support calls over 2 weeks. Our primary outcomes were reduced numbers of nightly wakes or parent report of sleep problem severity. Secondary outcomes included improvement in parental depression, fatigue, sleep, and parent cognitions about infant sleep.

Methods

Two hundred thirty five families of six-to-eight month-old infants were randomly allocated to intervention (n = 117) or to control teaching sessions (n = 118) where parents received instruction on infant safety. Outcome measures were observed at baseline and at 6 weeks post intervention. Nightly observation was based on actigraphy and sleep diaries over six days. Secondary outcomes were derived from the Multidimensional Assessment of Fatigue Scale, Center for Epidemiologic Studies Depression Measure, Pittsburgh Sleep Quality Index, and Maternal (parental) Cognitions about Infant Sleep Questionnaire.

Results

One hundred eight intervention and 107 control families provided six-week follow-up information with complete actigraphy data for 96 in each group: 96.9 % of intervention and 97.9 % of control infants had an average of 2 or more nightly wakes, a risk difference of −0.2 % (95 % CI: −1.32, 0.91). 4 % of intervention and 14 % of control infants had parent-assessed severe sleep problems: relative risk 0.3, a risk difference of −10 % (CI: 0.11, 0.84-16.8 to −2.2). Relative to controls, intervention parents reported improved baseline-adjusted parental depression (CI: −3.7 to −0.4), fatigue (CI: −5.74 to −1.68), sleep quality (CI: −1.5 to −0.2), and sleep cognitions: doubts (CI: −2.0 to −0.6), feeding (CI: − 2.1 to - 0.7), anger (CI: − 1.8 to - 0.4) and setting limits (CI: −3.5 to −1.5).

Conclusions

The intervention improved caregivers' assessments of infant sleep problem severity and parental depression, fatigue, sleep, and sleep cognitions compared with controls.

Trial registration

ISRCTN42169337, NCT00877162

Bedtime problems and night wakings in young children: an update of the evidence

Bedtime problems and night wakings in infants and young children are prevalent, persistent, and associated with a variety of impairments in youth and their families. Assessment strategies include clinical interview, sleep diaries, actigraphy, and subjective measures. A number of treatment approaches with varying degrees of empirical support are available, and several novel strategies have been evaluated in recent years. Appropriate sleep scheduling and a bedtime routine are important components of any treatment program.

Troubled sleep: Night waking, breastfeeding and parent-offspring conflict

Disrupted sleep is probably the most common complaint of parents with a new baby. Night waking increases in the second half of the first year of infant life and is more pronounced for breastfed infants. Sleep-related phenotypes of infants with Prader-Willi and Angelman syndromes suggest that imprinted genes of paternal origin promote greater wakefulness whereas imprinted genes of maternal origin favor more consolidated sleep. All these observations are consistent with a hypothesis that waking at night to suckle is an adaptation of infants to extend their mothers’ lactational amenorrhea, thus delaying the birth of a younger sib and enhancing infant survival.