Infant Sleep and Postpartum Maternal Mood

• In Event: Poster Session 04
  In Poster Session: PS 04 Topic - Family Context & Processes

Abstract

Approximately 20% of new mothers experience postpartum depression (Gavin et al., 2005). Depressive symptoms are associated with reduced warmth during mother–child interactions (Humphreys et al., 2018), and with decreased empathy toward one’s own child (Salo et al., 2020). One well-documented predictor of depressive symptoms in early motherhood is the sleep disturbances experienced in the postpartum period (Okun, 2016). More fragmented sleep may be a particularly important predictor of parental mood and behavior (King et al., 2020). At one month, infants wake an average of 15 times per night, and by 3 months the number reduces to an average of 9 night wakings (McDaniel & Teti, 2012). Thus, in the first few months of a new infant’s life mothers are experiencing significantly fragmented sleep. The relation between infant sleep and maternal depression, such that poorer quality infant sleep is associated with increased maternal depressive symptoms, is believed to emerge in early postpartum. However, studies typically examine these patterns later in infancy (> 6 months; Hiscock & Wake, 2001; Karraker & Young, 2007), well after symptoms of postpartum depression typically emerge and patterns of parent–infant interaction are established. Further, extant studies focus on inter-individual variability, often ignoring intra-individual variability. The current study takes advantage of intensive sampling of a single mother–infant dyad by assessing infant sleep, maternal sleep, and maternal mood on a daily basis. In this way, we are able to depict potential coupling of infant sleep and maternal mood in the immediate postpartum period and assess longitudinal changes every day across the first 4 months (120 days) following birth. To assess infant sleep we used a ‘smart’ bassinet which tracks amount of infant sleep as well as the number of infant wakings. The dyad used the provided bassinet nightly from birth and for the duration of the study. Maternal sleep quality was measured subjectively, via self-report, and objectively, via an under-mattress sleep monitor. The mother also completed daily surveys assessing current mood. For the current study we specifically focused on self-reported negative affect. Correlations among all measures can be found in Table 1. Maternal negative affect was significantly associated with maternal subjective sleep quality, infant wakings, and nightly longest span of infant sleep each. When considered within the same model, infant wakings remained a significant predictor of maternal mood, B=1.09, SE=0.24, p<.001, while longest infant sleep did not, B=0.001, SE=0.14, p=.99. Analyses that examined patterns across a day-to-day basis suggest infant wakings had a significant (Granger) causal influence on maternal wakings, F=4.94, p=.003 and maternal negative affect, F=4.38, p=.005. Infant wakings were not, however, predictive of maternal subjective sleep quality, F=1.53, p=.21. See Figure 1 for plot of the raw data. Data collection with a second mother–infant dyad is currently underway. The multimethod intensive sampling design provides unique insight into the intraindividual longitudinal coupling of infant sleep and maternal mood in the postpartum period, and suggests that objective assessment of infant sleep is a stronger predictor of maternal mood than her own wakings and sleep quality.

Authors

• Virginia Charlotte Salo, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD/NIH)
  Presenting Author

• Kathryn Humphreys, Vanderbilt University
  Non-Presenting Author