0121 Newborn Hair Cortisol and Sleep Health in Infancy

Abstract

Abstract Introduction Poor sleep health in infancy is linked to compromised physical and mental health in adulthood. As a result, identifying predictors of infant sleep health is essential for promoting lifelong health. A potential predictor that has been largely untested is fetal hypothalamic-adrenal-pituitary (HPA) axis functioning, which is linked to sleep behaviors and has been implicated in the development of sleep disorders. Cortisol, the end product of the HPA axis, may be important in regulating sleep during the early postnatal period. However, very little is known about the relation between fetal cortisol and offspring sleep in infancy. The current study aims to test the associations between neonatal hair cortisol, an index of fetal cortisol production in the third trimester, and sleep health in infancy. Methods Shortly after birth (M(days)=1.73, SD(days)=2.30), hair cortisol was collected from 70 infants (57.1% female) within the Care Project, a longitudinal study in Denver, Colorado. Participants did not receive exogenous glucocorticoids prenatally. Infant sleep health was assessed using parent report on the Brief Infant Sleep Questionnaire (BISQ) at 7 months of age. The BISQ includes measures of nighttime sleep duration, time spent in wakefulness during the night, number of night awakenings, and nighttime sleep onset latency. Partial correlations were conducted to examine the relation between newborn hair cortisol and sleep health, controlling for gestational age at birth and family income-to-needs ratio. Results Greater neonatal hair cortisol predicted longer sleep onset latency at 7 months (r=.32, p=.017), controlling for gestational age at birth and income-to-needs. Neonatal hair cortisol was not correlated with nighttime sleep duration (r=-.17, p=.21), nighttime wake duration (r=.13, p=.36), and number of night awakenings (r=-.13, p=.32). Conclusion Higher levels of fetal cortisol may negatively affect infant sleep health. Specifically, cortisol may inform the shift from multiphasic to monophasic sleep as well as the accumulation of sleep pressure throughout the day, impacting sleep onset latency. Future studies should consider the long-term effects of fetal cortisol production on sleep health in infancy and potentially later in life. Support (if any) This work is supported by the National Institutes of Health R01MH109662, R01HL155744, K01HL143159, F32HL165844, and diversity training supplement 3R01HL155744-01S3.