About half of US children experience significant sleep issues, according to the American Academy of
Pediatrics. Sleep health is critically important to a child’s overall health, including physical, cognitive, and
behavioral development. Further, sleep characteristics in childhood can persist into adolescence and then
adulthood. It is possible that sleep health may be affected or programmed by factors experienced in utero.
Fetal development is sensitive to common environmental chemicals like perfluoroalkyl substances (PFAS),
which are highly prevalent among US mothers. PFAS are endocrine disruptors, meaning they can disrupt the
body’s normal hormonal processes, crucial to the healthy development of the fetus. It is clear that chemical
exposures in pregnant mothers can lead to health problems for their infants that continue into childhood and
adolescence. Further, assessments of PFAS-related health outcomes using a mixtures approach are being
called for by regulators, given that typical human exposure involves complex combinations of PFAS. In
addition, preliminary IKIDS findings indicate a sex-specific association between certain PFAS and sleep
disturbance, where boys’ sleep was more affected by PFAS exposure during pregnancy than girls for two
specific PFAS in our current sample. The proposed project would use novel statistical methods to assess
associations between PFAS exposure during the prenatal period and child sleep quality longitudinally across
early childhood, using multiple measures of sleep. PFAS are measured in maternal blood collected at 16-18
weeks’ gestation, and sleep outcomes in young children are measured with three validated parent-report
measures capturing different aspects of sleep—disturbance, impairment and sleep problems. We propose to
leverage existing data from a prospective cohort of pregnant women and their children based in central Illinois,
known as the Illinois Kids Development Study, or IKIDS. Specifically, we will assess the longitudinal effects of
prenatal exposure to 12 perfluoroalkyl substances on sleep problems at ages 2, 3, and 4 (aim 1), as well as
PFAS mixtures on sleep disturbance, and impairment at age 4 alone (aim 2). Sleep disturbance and sleep
impairment are parent-report Patient-Reported Outcomes Measurement Information System (PROMIS)
measures and sleep problems is one of the syndrome scales of the preschool Child Behavior Checklist. Child
Prenatal PFAS exposure has been shown to be associated with neurodevelopmental outcomes in children, yet
there is no literature pertaining to prenatal PFAS effects on sleep quality during early childhood. Both PFAS
and child sleep problems are highly prevalent, and preliminary findings show that PFAS exposure in utero may
be responsible for some portion of the attributable risk of sleep problems in children. Yet, the area remains
vastly understudied. Given that sleep is so crucial to a child’s overall health and development, identifying
prevalent and persistent environmental factors that influence sleep health could have a substantial public
health impact.