Sleep duration trajectories from age 3 to 48 months in The Pelotas (Brazil) 2004 Birth Cohort Study

Infants' early recovery from sleep disturbance is associated with a lower risk of developmental delay in the Japan Environment and Children's Study

To examine whether patterns, such as the timings of onset or recovery from sleep disturbance, are associated with later developmental problems, including autism spectrum disorder (ASD). Mothers participating in the Japan Environment and Children's Study with a child aged 3 years were included in the analyses. Children were assessed for short sleep and frequent awakenings at 1 month, 6 months, and 1 year of age. Developmental problems were evaluated at 3 years of age based on ASD diagnosis and developmental delay, using the Japanese translation of the Ages and Stages Questionnaire (ASQ) 3rd edition. Sleep disturbance patterns were classified by onset age, and developmental problem risks were examined based on onset/recovery ages. Among 63,418 mother-infant dyads, 0.4% of infants were later diagnosed with ASD, and 14.4% had abnormal scores on any ASQ domains. The later the onset of short sleep, the lower the risk of abnormal ASQ scores (RR of short sleep onset at 1 year: 1.41; 6 months: 1.52; 1 month: 1.57). The earlier the infants recovered from short sleep persistence, the lower the risk of developmental delay (RR of remittance of sleep problems identified at 1 month by 6 months: 1.07; 1 year: 1.31; not before 1 year: 1.57). Although not all patterns were significant, later short sleep onset and earlier recovery were associated with lower ASD risk. These findings may have significant implications for future interventions in infant development.

Group-based sleep trajectories in children and adolescents: A systematic review

Sleep is crucial for health and development. Evidence indicates that sleep changes over time and distinct subgroups may experience different longitudinal patterns. This study systematically reviewed the studies that used latent trajectory modeling to investigate sleep trajectories of children and adolescents aged 0-18 years, and summarized the associated determinants and health-related outcomes. We searched PubMed, Embase, CENTRAL, PsycINFO, and Web of Science, identifying 46 articles that met our criteria. To ensure the reliability of the review, only studies rated as good or fair in terms of methodological quality were included, resulting in a total of 36 articles. Group-based trajectories were identified on several sleep dimensions (i.e., sleep duration, general and specific sleep problems, and bed-sharing behavior) and three or four trajectories were reported in most studies. There was a convergence trend across sleep duration trajectories during the first six years of life. Studies on specific sleep problem (i.e., insomnia, night-waking, and sleep-onset difficulties) typically identified two trajectories: consistent, minimal symptoms or chronic yet fluctuating symptoms. Lower socioeconomic status, maternal depression, and night feeding behaviors were the most frequently reported determinants of sleep trajectories. Membership in a group with certain adverse patterns (e.g., persistent short sleep duration) was associated with increased risks of multiple negative health-related conditions, such as obesity, compromised immunity, neurological problems, substance use, or internalizing/externalizing symptoms. Generally, there is potential to improve the quality of studies in this field. Causality is hard to be inferred within the current body of literature. Future studies could emphasize early life sleep, incorporate more assessment timepoints, use objective measures, and employ experimental design to better understand changes of and mechanisms behind the various sleep trajectories and guide targeted interventions for at-risk subpopulations.

Association between iron deficiency anemia and sleep duration in the first year of life

OBJECTIVE

The aim of this study was to investigate the association between iron deficiency anemia and sleep duration in the first year of life.

METHODS

A total of 123 infants were investigated, with sleep being evaluated at 3, 6, and 12 months of age and anemia at birth and 6 months. The cutoff points for anemia and short sleep duration were hemoglobin <11 g/dL (at birth and/or 6 months) and <10 h (at 3, 6, and 12 months), respectively. The comparison of the average sleep time between infants with and without anemia was performed using the Student's t-test, and logistic regression models were also used to verify differences in the sleep duration (short/not short) between the groups. Linear regression analyses were conducted to determine the association between sleep duration and hemoglobin values. The analyses were adjusted for potential confounders.

RESULTS

Children with anemia were more likely to be short sleepers [odds ratio (95% confidence interval (CI)): 4.02 (1.02-15.76); p≤0.05], and for each unit increase in hemoglobin values, the sleep duration increased by 16.2 min [β (95%CI): 0.27 (0.00-0.55); p≤0.05), regardless of family income, maternal schooling, gender, and body mass index at birth.

CONCLUSIONS

Our results suggest that iron deficiency anemia is associated with short sleep duration in the first year of life and indicate the need for longitudinal investigations, with longer follow-up, to verify the impact of anemia on sleep duration at subsequent ages.

Perinatal Physiological and Psychological Risk Factors and Childhood Sleep Outcomes: A Systematic Review and Meta-analysis

OBJECTIVES

The purpose of this study was to investigate the influence of maternal physiological and psychological factors during pregnancy and after birth on infant and children's sleep outcomes.

METHODS

Six databases were searched from inception to April 2021. Longitudinal studies that investigated the association of risk factors during and after pregnancy and children's sleep-related outcomes were included. Hedge's g and odds ratio were pooled as effect size with random effects model.

RESULTS

A total of 32 articles were included. Both prenatal maternal alcohol use (odds ratio [OR] = 1.85, 95% confidence interval [CI]: 1.04-3.28) and tobacco smoking (OR = 1.28, 95% CI: 1.01-1.62) were associated with shorter child sleep duration. Prenatal and postnatal maternal depression symptoms were associated with increased child sleep problems at age 6 months (OR = 1.97, 95% CI: 1.19-3.24, and 2.05, 95% CI: 1.37-3.07, respectively). Prenatal and postnatal maternal major depression disorders were associated with shorter sleep duration (Hedge's g = -0.97, 95% CI: -1.57 to -0.37) and lower sleep efficiency (Hedge's g = -1.44, 95% CI: -1.93 to -0.95). Prenatal anxiety had no impact on child sleep problems (OR = 1.34, 95% CI: 0.86-2.10).

CONCLUSION

Maternal pregnancy and obstetric factors and psychological factors are potential risk factors of poor child sleep health. Future research is warranted to better understand the impact of these risk factors on long-term child sleep outcomes and their potential mediating mechanisms.

Association of sleep quality with temperament among one-month-old infants in The Japan Environment and Children’s Study

This study aimed to examine the association between infant sleep quality and temperament in one-month-old infants using a large cohort study data. We used data from the Japan Environment and Children’s Study, a cohort study which follows around 100,000 women from pregnancy until their children’s development. The mothers were asked about their infants’ sleep and temperament using a structured questionnaire. Frequent crying (adjusted odds ratio [AOR]: 1.05, 95% confidence interval [CI]: 1.00–1.10) and intense crying (AOR: 1.19, 95% CI: 1.13–1.25) were positively associated with longer sleep periods during the day than at night. Female infants with longer daytime sleep periods than that at nighttime were more likely to cry frequently (AOR: 1.11, 95% CI: 1.04–1.20). Parous women with infants who had frequent night awakening believed their infants cried more intensely (AOR: 1.17, 95% CI: 1.03–1.31). The study demonstrated a specific association between sleep quality and temperament in one-month-old infants. Based on the results of this study, further sleep intervention studies are required to improve infant temperament.