What affects the age of first sleeping through the night?

Possible contribution of better maternal psychological well-being to the acquisition of sleeping through the night in infants during the early postpartum period

The objective of this study was to elucidate whether better maternal psychological well-being contributes to the acquisition of "sleeping through the night" (STN) in infants during the early postpartum period. Fifty-two primiparous mothers completed the General Health Questionnaire-28 (GHQ-28) in the third trimester (prenatal) and when the conceptional ages of their babies reached 8-9 weeks (hereafter, 2 months), 12-13 weeks (3 months), and 16-17 weeks (4 months). They also recorded babies' nocturnal sleep patterns in a timetable for 5 consecutive days each month postpartum. "Regular STN" was defined when the mean of longest nocturnal sleep duration for 5 consecutive days was > 8 h or between 6 and 8 h with < 1.0 nocturnal awakenings. According to these criteria, a total of 14 infants (27 %) acquired regular STN at 4 months (referred to as "STN infants"), with STN infants showing a marked increase in longest nocturnal sleep duration and a decrease in nocturnal awakenings from 2 to 3 months of age. The mothers of STN infants demonstrated steady reductions in postnatal GHQ-28 scores and had significantly lower prenatal GHQ-28 scores compared with the mothers of non-STN infants (3.7 ± 3.0 vs. 6.4 ± 4.1, p = 0.027). In random forest models for binomial classification, both prenatal and postnatal (at 4 months) GHQ-28 scores were identified as significant covariates for distinguishing STN infants, and other important covariates, including weeks of delivery, stepfamily, birth weight of the infant, and maternal co-sleeping at bedtime, were selected. Among these covariates, maternal co-sleeping at bedtime had relatively stronger correlations with both STN infants (r = - 0.440) and prenatal maternal GHQ-28 scores (r = 0.377). In conclusion, because prenatal maternal psychological well-being was thought to predict the acquisition of STN in infants, infants born from mothers with better psychological well-being appear to have some advantages in acquiring STN. These cross-lagged correlations suggest that the pathway from mothers to infants may be mediated by certain parenting behaviors, such as maternal co-sleeping at bedtime.

Maternal emotions during the first three postnatal months: Gaining an hermeneutic understanding

BACKGROUND

Maternal emotions in the first three postnatal months are rarely explored yet in the German context despite it is known that they play an important role in the complexity of maternal health and well-being.

AIM

Gaining understanding of maternal emotions and how the developmental process of the infant circadian rhythm influences them during the first three months of the postnatal period.

METHODS

A Gadamerian-based research method was used to explore the experiences of 15 mothers in Germany.

FINDINGS

'Being needed' and 'being in need' emerged as the first two themes and were further explored hermeneutically. This resulted in the findings of 'emotional balance and conflicting emotions' as underlying maternal emotions during the first three months following birth.

DISCUSSION

Understanding maternal emotions during the first three months of the postnatal period has the potential of opening new pathways for improving maternal health and well-being.

CONCLUSION

A spectrum of maternal emotions, maternal uncertainties and maternal needs exists in the first three months of the postnatal period.

Infant sleep and its relation with cognition and growth: a narrative review

OBJECTIVE

Infant sleep development is a highly dynamic process occurring in parallel to and in interaction with cognitive and physical growth. This narrative review aims to summarize and discuss recent literature and provide an overview of the relation between infant sleep and cognitive development as well as physical growth.

METHODS

We conducted online literature search using MEDLINE, Embase, and Cochrane Library databases. We considered original research on humans published in the English language from January 2005 to December 2015. Search terms included "sleep" AND "infant" AND "cognition" OR "memory" OR "executive functioning", OR "growth" OR "obesity" OR "growth hormone" OR "stunting", and combinations thereof.

RESULTS

Ten studies on infant sleep and cognition were included in this review. Overall, findings indicated a positive association between sleep, memory, language, executive function, and overall cognitive development in typically developing infants and young children. An additional 20 studies support the positive role of infant sleep in physical growth, with the current literature focusing largely on weight gain and obesity rather than healthy growth. Existing evidence in both the domains is mainly based on cross-sectional designs, on association studies, and on parental reports. In contrast, there were limited studies on longitudinal sleep trajectories and intervention effects, or studies have not used more objective sleep measures such as actigraphy and polysomnography.

CONCLUSION

The reviewed studies support a critical and positive role of infant sleep in cognition and physical growth. Future studies should consider key environmental and parental confounders, include a combination of more objective (actigraphy) and subjective measures (sleep diaries and questionnaires), and move towards longitudinal trajectory designs of infant sleep and development.

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

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

Reactivity and sleep in infants: a longitudinal objective assessment

Sleep patterns and temperament in the first year of life are closely related. However, research utilizing objective, rather than subjective measurements of sleep and temperament is scarce and results are inconsistent. In addition, a relative lack of longitudinal data prevents inference of causality between the two constructs. In this study, infant sleep was objectively assessed among 95 infants at 3, 6, and 12 months-of-age with an actigraph in the home setting. Reactivity to sound, light, and touch, a specific aspect of temperament, was behaviorally assessed at 3 and 6 months, both during sleep (at home) and during waking (at the laboratory). Expected maturational trends were recorded in sleep, with a temporal increase in sleep efficiency and percent of motionless sleep. Quadratic (i.e., inverse U shape) relations were found, especially among girls, when predicting change in sleep by reactivity thresholds, suggesting that both hyposensitive and hypersensitive infants are at risk for poor sleep quality. These are the first research findings suggesting that low reactivity in infancy might be associated with compromised sleep quality. The observed nonlinear effects may account for null or inconsistent results in previous studies that explored only linear associations between temperament and sleep. Future studies should address both extremes of the temperament continuum when exploring relations with sleep patterns.

Very preterm infants show earlier emergence of 24-hour sleep-wake rhythms compared to term infants

BACKGROUND

Previous studies show contradictory results about the emergence of 24-h rhythms and the influence of external time cues on sleep-wake behavior in preterm compared to term infants.

AIMS

To examine whether very preterm infants (<32 weeks of gestational age) differ in their emergence of the 24-h sleep-wake rhythm at 5, 11 and 25 weeks corrected age compared to term infants and whether cycled light conditions during neonatal intermediate care affects postnatal 24-h sleep-wake rhythms in preterm infants.

STUDY DESIGN

Prospective cohort study with nested interventional trial.

SUBJECTS

34 preterm and 14 control term infants were studied. During neonatal hospitalization, preterm infants were randomly assigned to cycled light [7 am-7 pm lights on, 7 pm-7 am lights off, n=17] or dim light condition [lights off whenever the child is asleep, n=17].

OUTCOME MEASURES

Sleep and activity behavior recorded by parental diary and actigraphy at 5, 11 and 25 weeks corrected age.

RESULTS

Sleep at nighttime and the longest consolidated sleep period between 12 pm-6 am was longer (mixed model analysis, factor group: p=0.02, resp. p=0.01) and activity at nighttime was lower (p=0.005) at all ages in preterm compared to term infants. Cycled light exposed preterm infants showed the longest nighttime sleep duration. Dim light exposed preterm infants were the least active.

CONCLUSIONS

Preterm infants show an earlier emergence of the 24-h sleep-wake rhythm compared to term infants. Thus, the length of exposure to external time cues such as light may be important for the maturation of infant sleep-wake rhythms. Trial registry number: This trial has been registered at www.clinicaltrials.gov (identifier NCT01513226).

Distinguishing infant prolonged crying from sleep-waking problems

OBJECTIVE

Infants who cry a lot, or are unsettled in the night, are common sources of concern for parents and costly problems for health services. The two types of problems have been linked together and attributed to a general disturbance of infant regulation. Yet the infant behaviours involved present differently, at separate ages and times of day. To clarify causation, this study aims to assess whether prolonged crying at 5-6 weeks (the peak age for crying) predicts which infants are unsettled in the night at 12 weeks of age (when most infants become settled at night).

METHODS

Data from two longitudinal studies are analysed. Infant crying data were obtained from validated behaviour diaries; sleep-waking data from standard parental questionnaires.

RESULTS

A significant, weak relationship was found between crying at 5-6 weeks and 12-week night waking and signalling in one study, but not the other. Most infants who met the definition for prolonged crying/colic at 5-6 weeks were settled during the night at 12 weeks of age; they were not more likely than other infants to be unsettled.

CONCLUSIONS

Most infants who cry a lot at 5-6 weeks of age 'sleep through the night' at 12 weeks of age. This adds to evidence that the two types of problematic behaviour have different causes, and that infant sleep-waking problems usually involve maintenance of signalling behaviours rather than a generalised disturbance.

Infant crying and sleeping: helping parents to prevent and manage problems

This article summarizes the current understanding of infant crying and sleeping problems, together with the implications of this understanding for services and research, with a focus on the first months of infancy.

Research priorities for parenting and child health: a Delphi study

AIM

This paper is a report of a study to identify research priorities of clinical staff working with families at a Western Australian centre for parenting.

BACKGROUND

Australian centres for parenting focus on children's needs while working in partnership with parents, families and their communities. These agencies incorporate primary healthcare strategies in their unique approach with families. Clinicians' research priorities at these centres have not been explored in an Australian context.

METHOD

In 2005, a Delphi study was conducted in which clinicians were asked to provide a list of five important issues relating to care provided to children, parents and their families. Research topics identified were then ranked for their importance to the family and clinicians. Finally, the top 10 research topics were ranked for priority.

FINDINGS

In round 1, 148 research topics were identified. Thirty-six topics were removed, due to the availability of existing evidence. Content analysis was used to collapse statements into 26 research questions, which were further classified into seven categories: parenting issues; sleep and settling issues; postnatal depression; evaluation and impact of programmes; staffing issues; centre marketing services and others. Issues relating to sleep and settling and postnatal depression were rated as top research priorities.

CONCLUSION

The priorities of clinicians working with families provide research direction for this Western Australian centre and potentially other centres in Australia and similar settings elsewhere in the world. The Delphi approach in determining clinicians' perceptions of relevant research areas may be useful to direct research in other contexts.

Understanding sleep-wake behavior and sleep disorders in children: the value of a model

PURPOSE OF REVIEW

Sleep-wake problems such as night wakings, excessive crying, or difficulties in falling asleep are frequent behavioral issues during childhood. Maturational changes in sleep and circadian regulation likely contribute to the development and maintenance of such problems. This review highlights the recent research examining bioregulatory sleep mechanisms during development and provides a model for predicting sleep-wake behavior in young humans.

RECENT FINDINGS

Findings demonstrate that circadian and sleep homeostatic processes exhibit maturational changes during the first two decades of life. The developing interaction of both processes may be a key determinant of sleep-wake and crying behavior in infancy. Evidence shows that the dynamics of sleep homeostatic processes slow down in the course of childhood (i.e., sleep pressure accumulates more slowly with increasing age) enabling children to be awake for consolidated periods during the day. Another current topic is the adolescent sleep phase delay, which appears to be driven primarily by maturational changes in sleep homeostatic and circadian processes.

SUMMARY

The two-process model of sleep regulation is a valuable framework for understanding and predicting sleep-wake behavior in young humans. Such knowledge is important for improving anticipatory guidance, parental education, and patient care, as well as for developing appropriate social policies.

9. Common causes of sleep disruption and daytime sleepiness: childhood sleep disorders II

There are strong associations between childhood sleep disorders and behavioural, concentration and mood problems. Sleep disorders caused and maintained by behavioural factors (eg, sleep-onset association disorder) are common in young children, and have a significant impact on families. Evaluation should include a medical history, a physical, neurological and developmental examination, a description of any nocturnal events or daytime effects of the child's disturbed sleep, and a good understanding of the family situation and parental management of the child. Management involves recognising the developmental age of the child and the family dynamics, and educating and supporting families in applying behavioural techniques to establish good sleep hygiene. Children with parasomnias (eg, night terrors) also benefit from good sleep hygiene, while those with respiratory or neurological causes of sleep disturbance should be referred for specialist treatment.