title: Development of infant and toddler sleep patterns: real-world data from a mobile application.
abstract: The aim of this study was to investigate the development of infant and toddler sleep patterns. Data were collected on 841 children (aged from birth to 36 months) via a free, publicly available, commercially sponsored iPhone app. Analyses were conducted on caregiver recordings of 156 989 sleep sessions across a 19-month period. Detailed visualizations of the development of sleep across the first 3 years of life are presented. In the first 3 months, sleep sessions primarily lasted less than 3.5 h throughout the day. Between 3 and 7 months old, sleep consolidated into two naps of about 1.5 h in length and a night-time sleep session of about 10.5 h. Across age groups, a negative relationship was observed between the start of bedtime and the length of the night-time sleep session (i.e. later bedtime is associated with a shorter night-time sleep period). The length of daytime sleep sessions (naps) varied with age, decreasing between 1 and 5 months old, and then increasing monotonically through 28 months. Morning wake time was observed to be invariant in children aged 5-36 months. Sleep patterns are ever-changing across the first few years with wide individual variability. Sleep patterns start to develop more clearly at 5-6 months, when longer night-time sleep duration begins and sleep consolidation occurs. Daytime sleep patterns appeared to become more consistent and consolidated later in age than night-time sleep. Finally, there is greater variability in bedtimes than wake times, with bedtimes having a greater influence on night-time sleep duration.
authors.affiliation: The Children's Hospital of Philadelphia, Philadelphia, PA, USA. jmindell@sju.edu.|Saint Joseph's University, Philadelphia, PA, USA. jmindell@sju.edu.
authors.forename: Jodi A
authors.initials: JA
authors.lastname: Mindell
authors.affiliation: Saint Joseph's University, Philadelphia, PA, USA.
authors.forename: Erin S
authors.initials: ES
authors.lastname: Leichman
authors.affiliation: Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors.forename: Jordana
authors.initials: J
authors.lastname: Composto
authors.affiliation: Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Lee
authors.affiliation: GiantSky, Philadelphia, PA, USA.
authors.forename: Bula
authors.initials: B
authors.lastname: Bhullar
authors.affiliation: Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors.forename: Russel M
authors.initials: RM
authors.lastname: Walters
mesh_terms: D017028:Caregivers; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007206:Individuality; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D063731:Mobile Applications; D012890:Sleep / Q000502:physiology*; D013997:Time Factors; D014741:Video Recording
keywords: child development; circadian patterns; internet; parents