Characteristics of sleep in children with heavy prenatal alcohol exposure

Abstract

Background: Sleep plays an important role in neurodevelopment. However, the effects of prenatal alcohol exposure on sleep quality have been understudied, despite reports of sleep disturbance in infants prenatally exposed to alcohol and elevated levels of sleep problems reported by caregivers of children with fetal alcohol spectrum disorders. The current study characterizes sleep in children with prenatal alcohol exposure using both objective (actigraphy) and subjective (questionnaires, sleep diaries) methods.

Methods: Participants aged 6-10 years, with and without prenatal alcohol exposure, were included in the study (alcohol-exposed [AE]: n = 35; control [CON]: n = 39). Objective sleep was measured via 24-h actigraphy for 2 weeks. Parents completed sleep diaries and sleep questionnaires (Children's Sleep Habits Questionnaire, Pediatric Sleep Questionnaire). Multivariate analysis of variance was used to characterize the sleep profile (objective, subjective) and examine group differences.

Results: There were no group differences on actigraphy metrics averaged across 2 weeks. However, the AE group showed significantly greater intraindividual variability on most actigraphy measures, particularly total sleep time, percent sleep, wake after sleep onset, and number of wake bouts. Parents reported significantly more sleep problems in the AE group than in the CON group, primarily driven by night wakings, parasomnias (e.g., sleepwalking), snoring, and daytime sleepiness. These effects were more severe in children >8.5 years of age.

Conclusions: Despite similar 2-week average sleep outcomes, children with prenatal alcohol exposure showed greater intraindividual sleep variability and parents reported more sleep problems related to sleep behavior and snoring. These difficulties with sleep may be related to other cognitive and behavioral outcomes. Importantly, sleep is a modifiable behavior, and interventions that focus on variability in sleep, particularly in sleep duration, can impact the quality of life in children with prenatal alcohol exposure and their families.

Keywords: actigraphy; fetal alcohol spectrum disorder; intraindividual variability; prenatal alcohol exposure; sleep.

Figure 1.

Distribution of sleep actigraphy measures (two-week average [left panel] and night-to-night variability [SD; right panel]) by group. The AE group showed significantly greater intraindividual variability in WASO, number of wake bouts, sleep time, percent sleep, and fragmentation index than the CON group. Note: ** p < .01, * p < .05. WASO = wake after sleep onset, SD = standard deviation.

Figure 2.

Multiple regression modeling [A and B] and univariate analysis of variance [C and D] results for group by age interaction. Sleep time variability (Sleep Time SD) and number of wake bouts variability (Wake Bouts SD) increased with age in children with AE (ps <.05), but not in controls. There were no significant group differences among the children less than 8.5 years of age, but in children greater than 8.5 years old, sleep time variability and wake bouts variability were significantly higher in children with AE compared to controls (ps < .05, with SEM error bar).

Figure 3.

Association between average sleep duration as measured by actigraphy and sleep diaries (in minutes; r = 0.72).

Figure 4.

Multiple regression modeling [A] and univariate analysis of variance [B] results for group by age interaction effect on CSHQ Total Score. CSHQ Total Score in children with AE increased with age, whereas there was no significant relationship in controls (p < .05). There were no significant group differences in CSHQ Total Score among children <8.5 years old, but in children >8.5 years old, AE scored significantly higher compared to CON (p < .05, with SEM error bar).