Low parental tolerance for infant crying: an underlying factor in infant sleep problems?

Parenting behaviours play a major role in the evolution of infant sleep. Sleep problems in infancy have been associated with excessive parental involvement at night‐time, and with shorter delays in response to infant night wakings and signalling. Infant crying and sleep problems are linked, yet little is known about the impact of parental responses to crying on infant sleep patterns. This study examined the hypothesis that lower parental tolerance for crying is associated with infant sleep problems. We studied 144 married couples divided into three groups: parents of infants suffering from night‐waking problems (i.e. the clinical group), parents of infants without sleep problems and childless couples. Crying tolerance was assessed using questionnaires, audio recordings of crying infants and using a novel paradigm, in which participants were shown a video of a crying infant and asked when they would intervene. Parents in the clinical group demonstrated shorter intervention delays in the crying infant clip (group effect: P < 0.0001), and tended to attribute more distress to the crying infants compared to parents in both control groups (P < 0.05). Additionally, women demonstrated lower tolerance for infant crying on most measures compared to men. Our results suggest that parents of sleep‐disturbed infants appear to have lower tolerance for infant crying, which may be a predisposition underlying their excessive involvement in soothing their infants to sleep which may lead to the development of sleep problems. These preliminary findings should be explored further to assess their clinical validity and utility.     

Pacifier Use,Finger Sucking,and Infant Sleep

Few studies to date have investigated the relationship between pacifier use or finger sucking and infant sleep. One hundred and four mothers of infants (ages 0–11 months) completed the Brief Infant Sleep Questionnaire (BISQ). Infants who engaged in finger sucking had fewer night wakings and longer stretches of nighttime sleep, although less daytime sleep. There were no significant differences in sleep patterns between pacifier users and infants who did not engage in nonnutritive sucking. Furthermore, no significant differences were found across groups for sleep ecology, including parental involvement at bedtime and following night wakings. Finally, infants were consistently able to retrieve their pacifiers independently by 7 months of age, although this did not appear to be associated with sleep outcomes. Results suggest that when parents are deciding whether to give their infant a pacifier, sleep may not be a critical factor. In contrast, parents of finger and thumb suckers should be reassured that this nonnutritive sucking is beneficial to sleep, at least in the first year of life.     

A behavioral-educational intervention to promote maternal and infant sleep: a pilot randomized, controlled trial

STUDY OBJECTIVES: Maternal and infant sleep are significant health concerns for postpartum families. The results of previously published studies have indicated that behavioral-educational strategies promote infant sleep, but these reports relied on parental report and did not include maternal sleep. This pilot study of a maternal-infant sleep intervention evaluated feasibility, acceptability, and effects on sleep and other outcomes in the early postpartum period. DESIGN: Randomized controlled trial with concealed-group allocation. SETTING: Hospital postpartum unit with home follow-up. PARTICIPANTS: First-time mothers and their infants randomly assigned to sleep intervention (n = 15) or control group (n = 15). INTERVENTIONS: The sleep intervention included a 45-minute meeting with a nurse to discuss sleep information and strategies, an 11-page booklet, and weekly phone contact to reinforce information and problem solve. The control group received a 10-minute meeting during which only maternal sleep hygiene and basic information about infant sleep were discussed, a 1-page pamphlet, and calls at weeks 3 and 5 to maintain contact without provision of advice. MEASUREMENT AND RESULTS: Questionnaires were completed at baseline and 6 weeks; sleep diaries and mother and infant actigraphy were completed at 6 weeks. The mothers in the sleep intervention group averaged 57 minutes more nighttime sleep, and fewer rated their sleep as a problem, as compared with the mothers in the control group. Infants in the sleep intervention group had fewer nighttime awakenings and had maximum lengths of nighttime sleep that were, on average, 46 minutes longer than those in the control group. CONCLUSIONS: A behavioral-educational intervention with first-time mothers in the early postpartum period promotes maternal and infant sleep. Further evaluation of the intervention in a larger, more diverse sample is needed.     

A Nightly Bedtime Routine: Impact on Sleep in Young Children and Maternal Mood

Background:

Establishment of a consistent bedtime routine is often recommended to parents of young children, especially those with sleep difficulties. However, no studies have investigated the efficacy of such a routine independent of behavioral intervention. Thus, the purpose of this study was to examine the impact of a consistent bedtime routine on infant and toddler sleep, as well as maternal mood.

Methods:

405 mothers and their infant or toddler (ages 7-18 months, n = 206; ages 18-36 months, n = 199) participated in 2 age-specific 3-week studies. Families were randomly assigned to a routine or control group. The first week of the study served as a baseline during which the mothers were instructed to follow their child''s usual bedtime routine. In the second and third weeks, mothers in the routine group were instructed to conduct a specific bedtime routine, while the control group continued their child''s usual routine. All mothers completed the Brief Infant Sleep Questionnaire (BISQ) on a weekly basis and a daily sleep diary, as well as completed the Profile of Mood States (POMS).

Results:

The bedtime routine resulted in significant reductions in problematic sleep behaviors for infants and toddlers. Significant improvements were seen in latency to sleep onset and in number/duration of night wakings, P < 0.001. Sleep continuity increased and there was a significant decrease in the number of mothers who rated their child''s sleep as problematic. Maternal mood state also significantly improved. Control group sleep patterns and maternal mood did not significantly change over the 3-week study period.

Conclusion:

These results suggest that instituting a consistent nightly bedtime routine, in and of itself, is beneficial in improving multiple aspects of infant and toddler sleep, especially wakefulness after sleep onset and sleep continuity, as well as maternal mood.

Citation:

Mindell JA; Telofski LS; Wiegand B; Kurtz ES. A nightly bedtime routine: impact on sleep in young children and maternal mood. SLEEP 2009;32(5):599–606.     

Effects of an Intervention Aimed at Reducing Night Waking and Signaling in 6- to 12-Month-Old Infants

This quasi-experimental one-group pre- and posttest pilot study evaluated an intervention aimed at reducing night waking and signaling for infants between 6 and 12 months of age. Thirty-nine healthy infants and their parents were recruited. Thirty-five infants completed the intervention and data collection. Both parents participated in a group teaching session with telephone follow-up for 2 weeks. Actigraphy and sleep diary data were collected at baseline and 6 and 16 weeks postintervention. We hypothesized a decrease in length and number of infant waking and crying periods and an increase in longest night sleep and nap time. Following the intervention, infants had significantly reduced length of night crying and number of wakes and longer night sleep periods. The intervention warrants evaluation with a randomized controlled design.     

Effects of an intervention aimed at reducing night waking and signaling in 6- to 12-month-old infants

This quasi-experimental one-group pre- and posttest pilot study evaluated an intervention aimed at reducing night waking and signaling for infants between 6 and 12 months of age. Thirty-nine healthy infants and their parents were recruited. Thirty-five infants completed the intervention and data collection. Both parents participated in a group teaching session with telephone follow-up for 2 weeks. Actigraphy and sleep diary data were collected at baseline and 6 and 16 weeks postintervention. We hypothesized a decrease in length and number of infant waking and crying periods and an increase in longest night sleep and nap time. Following the intervention, infants had significantly reduced length of night crying and number of wakes and longer night sleep periods. The intervention warrants evaluation with a randomized controlled design.     

The effects of a session of resistance training on sleep patterns in the elderly

The purpose of this study was to evaluate the influence of a session of resistance training on the sleep patterns of elderly people. Forty men aged 65-80 years who were sedentary and clinically healthy were divided into two groups: the control group (n = 18) and the resistance group (n = 22). Both groups underwent two polysomnography tests, one at baseline and another after either a resistance training session (the resistance group) or no physical exercise (the control group). The resistance training session was based on 60% of one repetition maximum (a test that assesses the maximum force). We observed that the frequency with which the control group awoke (arousal index) increased from 16.29 ± 6.06 events/h to 20.09 ± 6.9 events/h, and in the resistance group, it decreased from 22.27 ± 11 events/h to 20.41 ± 8.57 events/h (t = 2.10 and p = 0.04). For stage-1 sleep, there was an increase from 4.96% at baseline to 5.40% in the control group, and there was a decrease in the resistance group from 8.32 to 6.21% after the exercise session (t = 2.12 and p = 0.04). A session of resistance training at 60% of one repetition maximum was able to modify the sleep pattern in men aged 65-80 years, suggesting that physical exercise has a modest influence on sleep consolidation.     

Sleep architecture in term and preterm infants beyond the neonatal period: the influence of gestational age, steroids, and ventilatory support

STUDY OBJECTIVE: To examine (1) sleep architecture of infants at varied risk for sudden infant death syndrome, (2) delays or advances in preterm infants at term postmenstrual age, (3) whether ventilatory support and gestational age alter sleep, (4) whether steroids alter sleep, (5) confounding influences of sex, small for gestational age, and maternal smoking. DESIGN: Overnight polysomnography. Dependent variables: Percentage of active sleep, quiet sleep, indeterminate, and awake time per total recording time; mean and longest duration of state epochs; number of episodes > or = 10 minutes; and sleep efficiency. SETTING: Collaborative Home Infant Monitoring Evaluation (CHIME). PARTICIPANTS: Two hundred one preterm and 198 term infants between 33 and 58 weeks postmenstrual age during polysomnography. Fifty-one term infants with an apparent life-threatening event without known etiology (apnea of infancy), 59 subsequent siblings of babies who died of sudden infant death syndrome, and 88 healthy term infants. RESULTS: Tracings of infants with apnea of infancy and healthy term infants were similar. Subsequent siblings of babies who died of sudden infant death syndrome spent less time in quiet sleep. Preterm infants (< or = 37 weeks postmenstrual age) exhibited immature architecture compared with infants of term postmenstrual age. The latter exhibited similar sleep except that they had a lower percentage of quiet sleep and longer mean indeterminate and longest indeterminate episodes. Preterm infants with the youngest gestational age lagged behind older preterm infants. Neither sex nor use of steroids affected sleep. Assisted ventilation was associated with a delay in maturation, small-for-gestational age status with increased active sleep, and smoking with increased awake time. CONCLUSION: With few exceptions, asymptomatic premature infants do not exhibit significant delays in sleep architecture compared with term infants at comparable postmenstrual age. The preterm infant with an early gestational age and morbidity exhibited delayed sleep architecture.     

Normal physiological patterns and physiological-behavioral correlations in unrestrained monkey infants

Utilizing a totally implantable biotelemetry system, we have recorded normal physiological data simultaneously with behavior in 4 unrestrained M. nemestrina monkey infants, ages 24, 24, 26, and 35 weeks, living with their mothers in their social group. Circadian body temperature rhythms, waking EEG rhythms, sleep patterns, and heart rate measurements were obtained, and were correlated with behavior. Sleep stage values and body temperature circadian rhythms showed relatively little intersubject variability. Heart rate and EEG patterns were more individually characteristic of a given monkey infant. Using both physiological and behavioral data collected in this manner, a bio-behavioral developmental profile for the monkey infant can be constructed. By comparing the infants position with respect to normative physiological and behavioral developmental indices for its chronological age, infants showing bio-behavioral developmental retardation or acceleration in one or several areas can be identified, and the underlying mechanisms investigated. We believe this capability will greatly enhance the value of the infant monkey as an animal model system of value to psychiatry and the behavioral sciences.     

Infants at risk for sudden infant death syndrome (SIDS): Differential prediction for three siblings of SIDS infants

The outcome for three siblings of SIDS (SSIDS) infants was predicted, using as a risk model the sleep and respiratory characteristics of a SIDS victim studied extensively during the neonatal period. The SIDS infant had shown unstable state organization and deviant respiration patterns, including a deficit of brief apneic pauses. Like the SIDS infant, the SSIDS infants and a group of 16 normal infants were observed in the home for 7-hr periods when they were 2, 3, 4, and 5 weeks old. Two of the infants showed normal sleep and respiratory characteristics, and they were predicted to develop without respiratory dysfunction. In contrast, the third infant showed a pattern of deviancies similar to the SIDS infant; and at 4 months, she had prolonged apneic episodes, requiring resuscitation on two occasions. The findings are consistent with the notion of subtle central nervous system (CNS) dysfunction in SIDS risk infants from the time of birth.The preparation of this paper was supported by Grant MH 41244 from the National Institute of Mental Health, Center for Prevention Research, Division of Prevention and Special Mental Health Programs.     

Physiological correlates of maternal separation in surrogate-reared infants: a study in altered attachment bonds.

Three pigtail infant monkeys (Macaca nemestrina) were separated from their mothers shortly after birth and raised in social isolation on cloth surrogates. At about 24 weeks of age they were surgically implanted with multichannel biotelemetry systems. Following the collection of baseline behavioral and physiological data, the cloth surrogates were removed for 4 days, then returned. The behavioral and physiological (heart rate, body temperature, sleep patterns) reaction to separation from the surrogate was much less intense than is the case in group-living pigtail infants that are separated from their mothers, suggesting that the attachment bond to a cloth surrogate may be different than the bond to a living mother in a social group. Heart rate mean values and variability were similar in surrogate-reared and mother-reared infants, suggesting a degree of environmental independence in heart rate regulation.     

Sleep Patterns among South Korean Infants and Toddlers: Global Comparison

The purpose of this study was to examine sleep patterns in a large sample of infants and toddlers (ages birth to 36 months) in Korea, and to compare sleep patterns, sleep problems, sleep ecology, and parental behaviors to global sleep data on young children in both predominately Asian (P-A) and predominately Caucasian (P-C) countries/regions. We additionally examined parent and child demographic information, parental behaviors, and aspects of the sleep ecology as predictors of sleep patterns among infants and toddlers in Korea. Parents/caregivers of 1,036 Korean infants and toddlers completed an expanded, internet-based version of the brief infant sleep questionnaire. Consistent with other studies of sleep in early childhood, sleep/wake patterns became increasingly consolidated with older child age for the Korea sample. Compared to both P-A and P-C infants and toddlers, children in Korea had the latest bedtimes, shortest total sleep and daytime sleep durations, and the least frequent rates of napping. Even though half of parents perceive their children’s sleep problematic, parental perceptions of severe child sleep problems were the lowest. Within Korea, breastfeeding and bottle-feeding at sleep resumption were associated with increased nocturnal awakenings. Evening television viewing was associated with later bedtimes, which may have implications for sleep hygiene recommendations in clinical practice. The current study provides important information about sleep/wake patterns, parental behaviors, and aspects of the sleep ecology for infants and toddlers for physicians to support healthy sleep in Korea.     

Comparison of postnatal development of heart rate responses to trigeminal stimulation in sleeping preterm and term infants

Autonomic dysfunction has been regarded as a possible cause of the sudden infant death syndrome (SIDS) and it has been suggested that preterm infants, who are at a greater risk of SIDS than term infants, may have immature autonomic control. Our aim was to compare the maturation of cardiac autonomic control during sleep in preterm and term infants by examining heart rate responses to arousing and non-arousing trigeminal stimuli. Preterm infants (n = 15) and term infants (n = 24) were studied longitudinally with daytime polysomnography. Air-jet stimulation of the nares was delivered in both active sleep (AS) and quiet sleep (QS), and heart rate (HR) changes recorded for both arousal and non-arousal responses. Changes in HR (DeltaHR%) were calculated as the relative differences between baseline HR (BHR) and either MaxHR (arousal) or MinHR (non-arousal). Comparisons of HR changes between sleep states and postnatal ages were made with two-way anova for repeated measures and between groups with two-way anova. The increase in HR (DeltaHR%) was greater in term than preterm infants (P < 0.05), but only at 2-3 weeks corrected postnatal age (CPA). In preterm infants, there were no differences in BHR between sleep states, whereas in term infants, BHR was higher in AS than in QS at 2-3 weeks and 2-3 months of age. The smaller DeltaHR% to arousing stimuli in preterm infants compared with term infants at 2-3 weeks suggests that cardiac sympathetic activity in preterm infants may be lower than in term infants. This mechanism may account for the increased risk for SIDS of preterm infants.     

Early preventive attachment-oriented psychotherapeutic intervention program with parents of a very low birthweight premature infant: results of attachment and neurological development

The birth of a very small preterm infant (< or = 1500 grams) can be a traumatizing experience for many parents. A developmental risk model is presented that is the background to an early attachment-oriented preventive psychotherapeutic intervention. This comprehensive parent-centered intervention program is composed of supportive group psychotherapy, attachment-oriented focal individual psychotherapy, a home visit and video-based sensitivity training. The intervention aims at improving parental coping, the process of attachment and parent-infant interaction. In a prospective longitudinal design mothers were randomly assigned to a control (N = 44) and an intervention group (N = 43) after preterm delivery. Results show that the percentage of secure (control vs. intervention group: 77.8% vs. 59.4%) and insecure (control vs. intervention group: 8.3% vs. 31.3% avoidant, 13.9% vs. 9.4% ambivalent) attachment quality in high-risk preterm infants is comparable to results from studies with term infants. There was no significant statistical difference in terms of quality of attachment of the preterm infants between the control group and the intervention group. However, only in the control group, impaired neurological development corresponded significantly with an insecure quality of attachment, but not in the intervention group, although there were significantly more neurologically impaired infants in the intervention group. This result is discussed as an effect of the intervention program.     

Urinary prolactin is correlated with mothering and allo-mothering in squirrel monkeys

The hormone prolactin is implicated in infant care-giving by parents and allo-parents in a variety of species. Adult female squirrel monkeys (Saimiri spp.) engage in allo-mothering behavior, which includes carrying and nursing infants, but communal care of offspring has not been investigated from an endocrine standpoint in this taxon. We attempted to fill this gap by examining prolactin levels in squirrel monkeys (Saimiri sciureus) as a function of parental responsiveness. Subjects were housed at the National Institutes of Health Animal Center and assays were performed at the Wisconsin National Primate Research Center. To test for the presence of prolactin in squirrel monkey, saliva, blood and saliva were simultaneously collected from anesthetized subjects during routine health examinations. Prolactin was detectable in serum but not in saliva samples. In the core investigation, behavioral data were collected by focal animal sampling on three 1-male multi-female groups, and individually identified urine was collected non-invasively from foil containers underneath group cages on a daily basis throughout the behavioral study. Changes in urinary prolactin over time reflected changes in the reproductive state of a female who was pregnant, gave birth and lactated during the study. Mean urinary prolactin levels in non-lactating females and a male housed with infants in one group were higher than in adults from 2 groups without infants. In the group with infants, mean urinary prolactin levels in adults increased with the amount of infant contact and care-giving. The squirrel monkey may represent a new primate model for investigating the endocrinology of infant care-giving.     

Judgments of infant pain: the impact of caregiver identity and infant age

OBJECTIVE: To examine whether caregiver judgments of infant pain would vary systematically with different infant caregiver groups and infant age. METHODS: A total of 123 caregivers (41 parents, 41 in patient nurses, 41 pediatricians) viewed videotapes of the vigorous behavioral responses of healthy infants (aged 2, 4, 6, 12, and 18 months) to a routine immunization injection and provided ratings of both the affective distress and pain intensity observed. RESULTS: A principal components analysis of affective and intensity ratings yielded a weighted pain summary score for each injection event. Older infants were attributed significantly more pain than younger infants, even though the vigor of the behavioral reactions was experimentally controlled across age groups. A profile analysis contrasting observer groups indicated that pediatricians attributed significantly lower levels of pain than parents, while nurses were intermediate to the other groups, not significantly differing from either group. These systematic differences in judgments were consistent across infant age groups. CONCLUSIONS: The findings reveal systematic sources of significant variations in observer judgments of infant pain. Despite an absence of differences in the behavioral reactions of the children, both the type of caregiver and their knowledge of the child's age systematically influenced attributions of pain to infants. This work suggests the important role of caregiver role variation and perceived developmental maturity as determinants of infant pain judgments and highlights potential areas of difficulty in controlling the unnecessary suffering of infants.     

Early preventive attachment-oriented psychotherapeutic intervention program with parents of a very low birthweight premature infant: Results of attachment and neurological development

The birth of a very small preterm infant ( 1500 grams) can be a traumatizing experience for many parents. A developmental risk model is presented that is the background to an early attachment-oriented preventive psychotherapeutic intervention. This comprehensive parent-centered intervention program is composed of supportive group psychotherapy, attachment-oriented focal individual psychotherapy, a home visit and video-based sensitivity training. The intervention aims at improving parental coping, the process of attachment and parent-infant interaction. In a prospective longitudinal design mothers were randomly assigned to a control (N = 44) and an intervention group (N = 43) after preterm delivery. Results show that the percentage of secure (control vs. intervention group: 77.8% vs. 59.4%) and insecure (control vs. intervention group: 8.3% vs. 31.3% avoidant, 13.9% vs. 9.4% ambivalent) attachment quality in high-risk preterm infants is comparable to results from studies with term infants. There was no significant statistical difference in terms of quality of attachment of the preterm infants between the control group and the intervention group. However, only in the control group, impaired neurological development corresponded significantly with an insecure quality of attachment, but not in the intervention group, although there were significantly more neurologically impaired infants in the intervention group. This result is discussed as an effect of the intervention program.     

Sleep in infant monkeys: Normal values and behavioral correlates

Measures of all night sleep physiology (EEG, EOG, EMG, heart rate (HR), body temperature (BT)) were recorded from 8 totally unrestrained infant M. nemestrina monkeys (mean age 26.1 weeks) for a total of 31 nights. Objective measurements of daytime behaviors were obtained in 7 of the infants. Mean sleep latency for the group was 35 min; individual sleep latency was related to maternal dominance. Mean total sleep time was 558 min, and mean sleep stage values for the group were drowsy, 16 min, Stage 2, 302 min, Stage 3–4, 150 min, and REM, 90 min. Mean interREM interval was 59.2 min. Infants exhibiting more locomotive behavior also had more Stage 3–4 sleep. Lower HR values were often found during deep slow wave sleep, but most nocturnal HR and BT variability did not appear closely associated with sleep patterns per se. Higher nocturnal body temperature and heart rate values were found in those infants engaging in greater amounts of play behavior and receiving more punishment from adults. Our findings are considered in terms of developing a biobehavioral developmental profile for the monkey infant.     

Aerobic exercise affects sleep,psychological wellbeing and immune system parameters among subjects with chronic primary insomnia

BackgroundChronic primary insomnia is characterized by long-term difficulties in maintaining and initiating sleep, too early waking up, poor mood, fatigue, impaired concentration and poor quality of life. Exercise training is recommended to prevent and alleviate sleep disorders.ObjectiveThe aim of the study was to investigate the influence of aerobic exercise training on quality of sleep, psychological wellbeing and immune system among subjects with chronic primary insomnia.Material and methodsEighty previously sedentary subjects with chronic primary insomnia subjects enrolled in this study, their age ranged from 35–56 years. All participants were randomly assigned to supervised aerobic exercise intervention group (group A, n=40) or control group (group B, n=40). Polysomnographic recordings for sleep quality assessment, Beck Depression Inventory (BDI), Profile of Mood States(POMS), Rosenberg Self-Esteem Scale (RSES), number of CD3+, CD4+, CD8+ T cells count and CD4/CD8 ratio were measured before and at the end of the study after six months.ResultsThere was a significant increase in the total sleep duration, sleep efficiency and sleep onset latency in group(A) after six months of aerobic exercise training, while, wake time after sleep onset and rapid eye movement (REM) latency significantly reduced after six months of aerobic training compared with values obtained prior to aerobic exercise training. Also, the mean values of BDI, POMS, CD3 count, CD4 count and CD8 count decreased significantly and the mean value of RSES significantly increased in group (A) after the aerobic exercise training, while the results of the control group were not significant. Moreover, there were significant differences between both groups at the end of the study.ConclusionExercise training can be considered as a non-pharmacological modalty for modifying sleep quality, psychological wellbeing and immune system among subjects with chronic primary insomnia.     

Ontogenesis of the states of sleep in rat,cat, and guinea pig during the first postnatal month

The behavioral and polygraphic characteristics of wakefulness and sleep were studied in 20 infant rats, 26 kittens, and 25 infant guinea pigs during their first month of postnatal life. In the infant guinea pig, the electrocorticographic (ECoG) patterns of sleep were similar to those of the adult, except for the absence of spindles during the first 3 weeks. In the rat and the cat, states of vigilance were not clearly differentiated in ECoG patterns during the first week; near the 8th day a fast, high amplitude ECoG appeared during paradoxical sleep (PS). The first signs of slow-wave sleep (SWS) appeared at 11 to 13 days of age in the rat and at 15 to 21 days in the cat. The greater the immaturity of the animal at birth, the greater was the amount of time spent in PS in the perinatal period. In the rat, which was born the most immature, the decrease in the percent time of PS was very rapid: 70 % at birth, it decreased to 12% on the 30th day. In the cat the decrease was slower. In the guinea pig, despite its relative maturity, the percent time of PS at birth was 7%, approximately double that in the adult. The length of extrauterine life as well as the degree of immaturity at birth, played a role in the development of the sleep-wakefulness cycle.