Being Born Too Small and Too Early May Alter Sleep in Childhood

Abstract

Study Objectives: Fetal growth restriction (FGR) occurs in up to 10% of pregnancies and is associated with increased risk of prematurity and neurodevelopmental impairment. FGR also alters sleep-state distribution in utero and maturation in infancy. Currently, limited data on the long-term associations of FGR and childhood sleep exist. Accordingly, we assessed the associations between preterm birth and FGR and sleep in children aged 5-12 years.Methods: Seventeen children born preterm and FGR, 15 children born preterm but appropriately grown (appropriate birth weight for gestational age [AGA]), and 20 term AGA children (controls) were studied using overnight polysomnography. Sleep macroarchitecture was assessed using standard criteria, and sleep microarchitecture was assessed using spectral analysis of the electroencephalogram (C4-M1) with total, δ (0.5-3.9 Hz), θ (4.0-7.9Hz), α (8.0-11.9 Hz), σ (12.0-13.9 Hz), and β power (14.0-30 Hz) calculated.Results: For sleep macroarchitecture, preterm FGR children had higher N2% compared with term AGA children (p < .05). Preterm AGA children had reduced total sleep time, NREM%, and sleep efficiency compared with term AGA children (p < .05 for all). For sleep microarchitecture, preterm FGR children had a higher amount of total, δ and α power compared with both groups (p < .05). Sigma and β power was lowest in the preterm AGA group compared with both groups (p < .05 for both).Conclusions: Prematurity and FGR were associated with altered sleep macro-and microarchitecture measures indicative of reduced sleep quantity and quality in childhood. As sleep disturbance can affect both behavior and neurodevelopment in children, sleep in FGR and preterm children warrants further investigation. Keywords: fetal growth restriction, preterm birth, pediatric, EEG spectral analysis, sleep. Statement of SignificanceFetal growth restriction (FGR) is a major obstetric complication affecting up to 10% of pregnancies leading to increased risk of preterm birth and neurodevelopmental impairment. FGR alters the development of sleep in fetal life and infancy; however, few studies have investigated the long-term impact on sleep. This novel study assessed both sleep macro-and microarchitecture in children born preterm and FGR. Being born preterm and FGR was associated with reduced sleep quality, whereas being born preterm with an appropriate birth weight for gestational age was associated with both reduced sleep quantity and quality. This study highlights the potential need for clinical follow-up of sleep and investigation of the effects of poor sleep on neurodevelopment in this population.

Disturbed sleep in children born extremely preterm is associated with behavioural and emotional symptoms

“…With reference to previous studies, our findings regarding night waking and sleep onset latency are commensurate with the excess of parent-reported night waking and longer sleep onset latency in extremely preterm children described previously [9]. There remains inconclusive evidence regarding the association of preterm birth with altered sleep duration given the increase in sleep duration described using parent report [9], no significant difference in sleep duration in some polysomnography/EEG studies [10,12], and one polysomnography and one actigraphy study indicating a shorter sleep duration in preterm versus term-born children [11,13]. Future studies should evaluate daytime sleepiness, ideally using self-report, given the excess of daytime sleepiness among children born extremely preterm in the present study, but not evidenced in children born very preterm compared with term-born children [8].…”

“…Using polysomnography, an excess of night waking was observed among very preterm children without severe developmental delay compared with term-born children at 8 years of age, however no difference in sleep duration or sleep efficiency was observed [10]. At 9 years of age, polysomnography revealed shorter sleep duration, a higher percentage of the sleep period spent awake and poorer sleep efficiency in children born at 24-36 weeks of gestation with appropriate weight for gestational age compared with children born at term [11]. In contrast, a study using electroencephalogram (EEG) found no difference in measures of sleep quality and duration between children born very preterm and at term at a mean age of 13 years, although this sample excluded children with below average IQ [12].…”

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

“…The included studies were conducted in the United States (n 5 3), Canada (n 5 1), Brazil (n 5 2), Europe (n 5 14), Asia (n 5 3), and Oceania (n 5 7). Three studies used retrospective longitudinal study design and asked parents to recall perinatal risk exposure, [29][30][31] while other studies used the prospective longitudinal design. Nine studies explicitly reported a population-based participant recruitment.…”

Associations between gestational age and childhood sleep: a national retrospective cohort study

“…Studies have suggested that school-aged preterm children had different sleep patterns compared to full-term children, such as having earlier bedtimes and earlier wake times [5][6][7], but had no difference in overall sleep duration [6,7]. Preterm children have been reported to have lower sleep quality, including more nocturnal awakenings [8,9], and consistent with this more "shallow" and less "deep" non-rapid eye movement sleep [9]. It has been suggested that irreversible adverse factors related to preterm birth, such as brain injury, altered brain maturation, and respiratory problems may precipitate poor sleep.…”