Mothers' postpartum sleep disturbance is associated with the ability to sustain sensitivity toward infants

Infancy is a period of rapid development when the quality of caregiving behavior may be particularly consequential for children's long-term functioning. During this critical period for caregiving behavior, parents experience changes in their sleep that may affect their ability to provide sensitive care. The current study investigated the association of mothers' sleep disturbance with both levels and trajectories of maternal sensitivity during interactions with their infants.

At 18 weeks postpartum, mothers and their infants were observed during a home-based 10-minute "free play" interaction. Mothers' nighttime sleep was objectively measured using actigraphy and subjectively measured using sleep diaries. Maternal sensitivity was coded in two-minute intervals in order to characterize changes in sensitivity across the free play interaction. We used exploratory factor analysis to reduce the dimensionality of the objective and subjective measures of mothers' sleep, identifying a subjective sleep disturbance and an objective sleep continuity factor.

Using multi-level modeling, we found that mothers with poorer objective sleep continuity evidenced decreasing sensitivity toward their infants across the interaction. Mothers' self-reports of sleep disturbance were not associated with maternal sensitivity.

Although future research is necessary to identify the mechanisms that may explain the observed association between poor sleep continuity and the inability to sustain sensitivity toward infants, mothers' postpartum sleep continuity may be one factor to consider when designing interventions to improve the quality of caregiving.

Clinicaltrials.gov, NCT01846585.