A transactional model of sleep-wake regulation in infants born preterm or low birthweight

Longitudinal sleep multi-trajectories from age 1 to 5.5 years and their early correlates: results from the Étude Longitudinale Française depuis l'Enfance birth cohort study

STUDY OBJECTIVES

To identify sleep multi-trajectories in children from age 1 to 5.5 years and their early correlates.

METHODS

We collected early family, maternal, and child characteristics, including children's nighttime sleep duration (NSD) and daytime sleep duration (DSD), night waking (NW), and sleep-onset difficulties (SOD), by parental phone interviews at age 2 months and 1-, 2-, 3.5-, and 5.5 years. Group-based multi-trajectory modeling identified sleep multi-trajectory groups. Multinomial logistic regression assessed associations with early factors.

RESULTS

We identified five distinct sleep multi-trajectory groups for NSD, DSD, NW, and SOD in 9273 included children. The "Good sleepers" (31.6%) and "Long sleepers" (31.0%) groups had low NW and SOD prevalence and shorter NSD but longer DSD in "Good sleepers" than in "Long sleepers." The "Good sleepers but few SOD" group (10.3%) had long NSD and DSD but a SOD peak at age 3.5 years; the "Improving NW and SOD" group (9.6%) showed short but rapidly increasing NSD to a plateau and high but decreasing NW and SOD; the "Persistent NW and SOD" group (17.5%) had persistent high NW and SOD. Maternal depression during pregnancy and sleep habits at age 1 (e.g. parental presence or feeding to fall asleep, sleeping at least part of the night away from own bed) were common risk factors associated with the most disordered sleep multi-trajectory groups.

CONCLUSIONS

We identified distinct sleep multi-trajectory groups and early life-associated factors in preschoolers. Most of the factors associated with the most sleep-disordered multi-trajectory groups are likely modifiable and provide clues for early prevention interventions.

Perinatal antecedents of sleep disturbances in schoolchildren

STUDY OBJECTIVES

Prematurity has been associated with an increased risk for sleep apnea. However, sleep disturbances in children born preterm have not been extensively investigated. Considering that determinants of sleep may originate early in life, the potential impact of prematurity on sleep disturbances later in life could be important. To establish the role of prematurity on sleep disturbances in a cohort of schoolchildren that were born preterm and compare them with healthy controls.

METHODS

A cohort of 147 schoolchildren, 45 born at term (≥37 weeks) and 102 very preterm (<32 weeks), was recruited and evaluated at school age (5-9 years). The Pediatric Sleep Questionnaire (PSQ) and the Sleep Disturbance Scale for Children (SDSC) were used to assess sleep disturbances in different domains.

RESULTS

PSQ score was significantly higher in former preterm children (0.26 ± 0.18 vs. 0.18 ± 0.14 in controls; p = 0.004), and SDSC total score was also significantly different among groups (21.7 ± 11.6 vs. 14.1 ± 12.6; p < 0.001). Regression models showed significant mean differences in PSQ score, total SDSC score, and two SDSC subscale scores (i.e. sleep-wake transition disorders, sleep-breathing disorders, and sleep hyperhidrosis) even after adjustment for confounders. Maternal age and type of delivery were not significantly associated with total PSQ scores.

CONCLUSIONS

Sleep disturbances may originate early in life since children born preterm exhibit an increased risk for developing long-term sleep problems. These findings may have important implications for management of preterm children and for implementation of early interventions focused on optimizing sleep habits.

Sleep Duration and Nocturnal Awakenings in Infants Born with Gestational Risk

OBJECTIVE

Infants born with gestation-related risks (low birth weight (LBW), small for gestational age (SGA), and prematurely born infants) are faced with a cascade of developmental issues. The aim of this study was to investigate whether infants with gestation-related risks have different patterns of parent-reported sleep duration and nocturnal awakenings than children without these risk factors.

METHODS

Information on sleep duration and nocturnal awakenings was obtained by parental report at age 6 and 18 months in the Norwegian Mother and Child Cohort Study, which is a population-based longitudinal pregnancy cohort study conducted at the Norwegian Institute of Public Health. Birth weight and gestational age were obtained from the Medical Birth Registry of Norway. Outcomes were related to birth weight, prematurity, and to being born SGA.

RESULTS

A total of 75,531 mother-child dyads were included. Compared with children without gestational risks, children born SGA and with LBW had shorter sleep duration, whereas children born prematurely had longer sleep duration at both time points. The infants born SGA and with LBW, but not the prematurely born children, had fewer nocturnal awakenings at 6 months, but all had more awakenings at 18 months.

CONCLUSION

Infants with gestation-related risks show distinct sleep patterns. We suggest that sleep assessment is included in the follow-up of high-risk infants. Future studies are needed to investigate the predictive value and functional importance of the sleep patterns for infants with gestation-related risks.

Effects of a supportive care bundle on sleep variables of preterm infants during hospitalization

Sleep is important for preterm infants' brain development, but they are frequently exposed to painful procedures in the neonatal intensive care unit (NICU) that disturb their sleep cycle and affect their growth. The purpose of this study was to examine the prolonged effects of a supportive care bundle (modulation of the infants' states, non-nutritive sucking, facilitated tucking, and oral sucrose feeding) on preterm infants' sleep variables (sleep efficiency, total sleep time, sleep latency, and frequency of wake bouts) during hospitalization. The team recruited 65 preterm infants (gestational age at birth 28-36 weeks, average birth weight 1,652 g) from a Level III NICU at a medical center in Taiwan. Infants were randomly assigned to one of two treatment conditions to be administered while receiving intrusive procedures: (1) control condition (usual care, including routine procedures, positioning, and gentle touch); or (2) intervention condition in which the supportive care bundle was added to usual care. Sleep variables were measured using actigraphy for a baseline of three continuous days on the 6th to 8th days after birth and again for 3 continuous days when infants weighed ≧1,950 g. Two forms of generalized estimating equation analyses with control of significant covariates were used for data analysis. The supportive care bundle not only significantly increased sleep efficiency and total sleep time but also significantly decreased duration of sleep latency and frequency of wake bouts. These results provide evidence to support the incorporation of the supportive care bundle into NICU clinical practice during intrusive procedures.

Sleep Characteristics and Temperament in Preterm Children at Two Years of Age

STUDY OBJECTIVES

We aimed to compare 2-year-old children born preterm with children born full term regarding: (1) sleep characteristics, (2) temperament, and (3) relations between sleep pattern and habits and temperament.

METHODS

The study included 51 preterm children with normal cognitive, language, and motor development (mean = 20.94 months, standard deviation [SD] = 4.08) and 57 full-term children (mean = 21.19, SD = 4.32). To assess sleep-related difficulties and habits and child temperament, mothers completed the following questionnaires: the (1) Sleep Disturbance Scale for Children-adapted (SDSC); (2) Brief Infant Sleep Questionnaire (BISQ); and (3) Italian Temperament Questionnaires-version 12-36 months (QUIT).

RESULTS

Preterm children needed less support to fall asleep and fell asleep more often alone in their own bed compared to those born at full term; however, preterm children showed more frequent sleep difficulties, such as restlessness and breathing problems during the night. In addition, preterm children had lower scores in the temperamental dimension of attention and higher scores in negative emotionality than full-term children. Finally, sleep problems were correlated with higher motor activity, lower social orientation and attention, and increased negative emotionality; a shorter nocturnal sleep duration was related to higher motor activity and lower inhibition to novelty whereas an earlier rise time was associated with lower attention and social orientation.

CONCLUSIONS

Preterm children showed sleep pattern problems and disturbance, predominance of attention problems, and negative emotionality related to sleep disruption.

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.

Mother-child interactions in the NICU: relevance and implications for later parenting

OBJECTIVE

This study examined the feasibility of observing mother-child interactions in the neonatal intensive care unit (NICU), whether NICU interactions related to later interactions, and how interactions related to child and maternal characteristics.

METHODS

The sample included 130 preterm infants and their mothers, observed in a feeding interaction in the NICU. Dyads were observed through 36 months postterm.

RESULTS

Observed maternal positive affective involvement and verbalizations in the NICU were associated with the same parenting behaviors at 24 months, social support, socioeconomic status, and being born in the late preterm period. Maternal negative affect and behavior were unrelated to later maternal negativity or child and maternal characteristics.

CONCLUSIONS

Positive parenting assessed in the NICU appears related to later parenting interaction quality, suggesting early assessment is possible. Maternal negative affect and behavior toward children may not consistently emerge until later in development.

Sleep and Attachment in Preterm Infants

Infants born preterm are at elevated risk for social emotional difficulties. However, factors contributing to this risk are largely understudied. Within the present study, we explored infant sleep as a biosocial factor that may play a role in infant social emotional development. Within a prospective longitudinal design, we examined parent-reported sleep patterns and observed parenting quality as predictors of infant-mother attachment in 171 infants born preterm. Using structural equation modeling, we examined main effect and moderator models linking infant sleep patterns and parenting with attachment security. Sleep patterns characterized by more daytime sleep and positive/responsive parenting predicted infant attachment security. Parent-reported nighttime sleep patterns were unrelated to attachment in this sample of infants born preterm. These results indicate that daytime sleep and parenting quality may be important for emerging attachment relationships in infants born preterm.

Effectiveness of part C early intervention physical, occupational, and speech therapy services for preterm or low birth weight infants in Wisconsin, United States

OBJECTIVE

To determine the effectiveness of policy-driven therapy (ie, Part C early intervention [EI]) in the context of varying maternal supports among preterm infants in Wisconsin.

METHODS

A longitudinal study of mother-infant dyads recruited from 3 newborn intensive care units in southeastern Wisconsin. Participation in EI-based therapy was collected at 36 months via parent-report. Cognitive function was measured at 16 months by use of the Bayley Scales of Infant Development (Mental Developmental Index), 2nd edition and at 24 and 36 months postterm via use of the Stanford-Binet Intelligence scale, 5th edition. Maternal support was measured at 4 months with the Maternal Support Scale. Propensity score matching was used to reduce selection bias. Latent growth models of matched pairs estimated the effect of EI therapy on cognitive function trajectories. Ordinary least squares regression estimated the differential effect of EI therapy on cognitive function at 16, 24, and 36 months postterm for mothers reporting more maternal supports.

RESULTS

Of the 128 infants, 41 received EI therapy and, of those, 32 (78%) were successfully matched with controls. The results of the matched analysis (n = 64) reveal that 1) receipt of therapy is inversely associated with cognitive function baseline (P = .04) and positively associated with trajectories (P = .03), 2) the number of maternal supports is positively associated with cognitive function for families receiving Part C early intervention, at 16 months (P = .05), 24 months (P < .01), and 36 months (P = .05) postterm.

CONCLUSIONS

Participation in EI therapy may be associated with more optimal cognitive function trajectories. Among preterm children whose mothers have more supports, receiving therapy appears particularly beneficial.

Causes and correlates of frequent night awakenings in early childhood

Night awakenings are a normative part of early development. In the first year, night awakenings are associated with birth order, feeding route, sleep aid use, sleep location, infant temperament and development, infant-parent attachment, family socioeconomics, and cultural norms. In the second year, additional factors build on these foundational features, including parenting practices and object attachment. As children grow, contextual factors like preschool entry or changes in family member status may influence the continuation or exacerbation of awakenings. Future research should consider the multitude of factors that influence not only awakenings but also parental perceptions, family dynamics, and cultural norms.

The impact of attachment insecurity and sleep disturbance on symptoms and sick days in hospital-based health-care workers

OBJECTIVE

Adult attachment insecurity is associated with many health outcomes and may be associated with sleep disturbance. The purpose of this study was to test the hypothesis that sleep disturbance mediates the relationship between attachment insecurity and three measures of health (perceived general health, physical symptoms and sick days) in a group that is at high risk of sleep disturbance: hospital based health-care workers.

METHODS

One hundred thirty-one nondepressed female hospital workers completed self-report measures of adult attachment, sleep disturbance, depressive symptoms (excluding sleep-related items) and health outcomes. The hypothesis of mediation was tested with sequential regression analyses.

RESULTS

Both attachment anxiety and attachment avoidance were significantly associated with impairment in global sleep quality (ρ=.20 and .19, respectively, P<.05) and physical symptoms (ρ=.21 and .19, P<.05). Attachment anxiety was also associated with depressive symptoms (ρ=.33, P<.001) and sick days (ρ=.21, P<.05). For both physical symptoms and sick days, mediation analyses were consistent with global sleep quality acting as a partial mediator of the relationship between attachment anxiety and physical health. Non-sleep-related depressive symptoms were a stronger mediator.

CONCLUSIONS

This study corroborates evidence that attachment insecurity is associated with sleep disturbance and extends this association to the occurrence of physical symptoms and time off work due to sickness among workers in a high-stress occupation.

Infant feeding methods and maternal sleep and daytime functioning

OBJECTIVE

Our purpose was to explore maternal actigraphically measured sleep, subjective sleep reports, and daytime functioning on the basis of current feeding method status during postpartum weeks 2 through 12.

METHODS

Objectively measured total sleep time, sleep efficiency, and fragmentation, subjectively reported numbers of nocturnal awakenings, total nocturnal wake time, and sleep quality, and sleepiness/fatigue measured by using the fatigue visual analog scale, the Stanford Sleepiness Scale, or the Epworth Sleepiness Scale were assessed.

RESULTS

We did not find differences between women who were exclusively breastfeeding, exclusively formula feeding, or using a combination of the 2 methods, with respect to the assessed parameters.

CONCLUSIONS

Efforts to encourage women to breastfeed should include information about sleep. Specifically, women should be told that choosing to formula feed does not equate with improved sleep. The risks of not breastfeeding should be weighed against the cumulative lack of evidence indicating any benefit of formula feeding on maternal sleep.