Bidirectional associations between maternal and infant sleep and mental health across the perinatal period

Introduction
The bidirectional relationship between sleep and mental health in the perinatal periods is still poorly understood, with infant sleep rarely considered in this relationship. This longitudinal study investigated the bidirectional relationships between maternal sleep, infant sleep, and maternal depressive and anxiety symptoms over five years.
Methods
This is a secondary data analysis of a randomised controlled trial on maternal sleep health. A community sample of nulliparous participants (N=163, Mage=33.47, SDage=3.52) self-reported depressive and anxiety symptoms, maternal sleep, and infant sleep collected via questionnaires at 30- and 35 weeks’ gestation, 1.5, 3, 6, 12 and 24 months postpartum. Data were analysed using cross-lagged panel analyses, controlling for intervention condition in the larger randomised controlled trial.
Results
Variables were generally associated with each other at the same timepoint and the same variable tended to predict itself at the prospective timepoint. Depressive symptoms at 30 weeks’ gestation predicted maternal insomnia symptoms at 35 weeks’ gestation. Infant night-time sleep duration at 1.5m predicted maternal anxiety at 3m postpartum. Maternal insomnia scores at 1.5m, 6m and 12m predicted maternal anxiety at 3m, 12m, and 24m respectively. Depression symptoms at 12m postpartum predicted maternal insomnia symptoms at 24m postpartum.
Discussion
There are bidirectional associations between maternal, infant sleep and maternal mental health, and the direction of these associations differed between perinatal stages. Future studies are needed to better understand these relationships and examine whether intervening on sleep or mental health may be protective of the other.