Grandparental care and sleep disturbances in preschool children: a population-based prospective cohort study

Sleep disturbances are common in preschoolers, and profoundly affected by parenting. Grandparents are increasingly involved in childcare and have attracted worldwide attention for their potential impacts on child well-being. However, no studies have explored child sleep health within the context of grandparental care. We aimed to explore the association between grandparents as primary caregivers and children's sleep disturbances.Participants included 20,324 preschoolers from the Shanghai Children's Health, Education and Lifestyle Evaluation-Preschool (SCHEDULE-P) in Shanghai, China. They were initially assessed in November 2016 and were reassessed in April 2018 and April 2019. Children's primary caregivers were collected at each survey. Sleep disturbances were assessed by the Children's Sleep Habits Questionnaire (CSHQ).At baseline, 84.4% of children had global sleep disturbances (CSHQ total score41). Compared with parents, random-effects model indicated that grandparents as primary caregivers increased the adjusted odds ratio (OR) for children's global sleep disturbances by 30% (OR [95%CI]: 1.30 [1.21, 1.40]). To the specific domains of CSHQ, two-way repeated-measures ANOVA showed significant "caregiver transition" group × wave interaction in the behavioral sleep disturbances, such as "Bedtime Resistance" (p 0.001). At each survey, children with grandparents as primary caregivers demonstrated significant higher behavioral sleep disturbances than their counterparts with parental care.Grandparental care is associated with increased sleep disturbances, particularly behavioral sleep disturbances, in preschoolers. Future studies should explore the underlying mechanisms and whether sleep programs targeting grandparents can decrease children's sleep disturbances.