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

Abstract

Background: Both sleep quality and quantity are essential for normal brain development throughout childhood; however, the association between preterm birth and sleep problems in preschoolers is not yet clear, and the effects of gestational age across the full range from preterm to post-term have not been examined. Our study investigated the sleep outcomes of children born at very-preterm (<31 weeks), moderate-preterm (32-33 weeks), late-preterm (34-36 weeks), early-term (37-38 weeks), full-term (39-40 weeks), late-term (41 weeks) and post-term (>41 weeks).

Methods: A national retrospective cohort study was conducted with 114,311 children aged 3-5 years old in China. Children's daily sleep hours and pediatric sleep disorders defined by the Children's Sleep Habits Questionnaire (CSHQ) were reported by parents. Linear regressions and logistic regression models were applied to examine gestational age at birth with the sleep outcomes of children.

Results: Compared with full-term children, a significantly higher CSHQ score, and hence worse sleep, was observed in very-preterm (β = 1.827), moderate-preterm (β = 1.409), late-preterm (β = 0.832), early-term (β = 0.233) and post-term (β = 0.831) children, all p<0.001. The association of pediatric sleep disorder (i.e. CSHQ scores>41) was also seen in very-preterm (adjusted odds ratio [AOR] = 1.287 95% confidence interval [CI] (1.157, 1.433)), moderate-preterm (AOR = 1.249 95% CI (1.110, 1.405)), late-preterm (AOR = 1.111 95% CI (1.052, 1.174)) and post-term (AOR = 1.139 95% CI (1.061, 1.222)), all p<0.001. Shorter sleep duration was also found in very-preterm (β = -0.303), moderate-preterm (β = -0.282), late-preterm (β = -0.201), early-term (β = -0.068) and post-term (β = -0.110) compared with full-term children, all p<0.01. Preterm and post-term-born children had different sleep profiles as suggested by subscales of the CSHQ.

Conclusions: Every degree of premature, early-term and post-term birth, compared to full-term, has an association with sleep disorders and shortened daily sleep duration. Preterm, early-term, and post-term should therefore all be monitored with an increased threat of sleep disorder that requires long-term monitoring for adverse sleep outcomes in preschoolers.

Keywords: Children’s sleep habit questionnaire; Daily sleep duration; Gestational age; Preschoolers; Sleep disorder.

Fig. 1

Flowchart of the study population. Legend: Detailed presentation of the inclusion and exclusion criteria of the study participant selection process and how the final number of the study cohort was established

Fig. 2

Associations of gestational age with daily sleep hours. Legend: Associations of gestational age with daily sleep hours: A Compared with full-term birth, preschool children born very-preterm, moderate-preterm, late-preterm, early-term and post-term were associated with lower daily sleep hours, all p < 0.01. B A fit spline described an inverse U-shape relationship of gestational age (weeks) with daily sleep hours (hours/day)

Fig. 3

Associations of gestational age with CSHQ score and sleep disorder. Legend: Associations of gestational age with CSHQ scores and sleep disorder. A Compared with full-term birth, preschool children born very-preterm, moderate-preterm, late-preterm, early-term and post-term were associated with higher CSHQ scores, all p < 0.001. B A fit spline described a U-shape relationship of gestational age (weeks) with CSHQ scores. C Compared with full-term birth, preschool children born very-preterm, moderate-preterm, late-preterm and post-term were associated with a higher prevalence of pediatric sleep disorder, all p < 0.001