(PS10-89) Postpartum Women Sleep Quality: Psychological Flexibility, Experiential Avoidance, and Sleep Beliefs

Abstract Text: Background
Sleep changes are a near ubiquitous experience for new mothers (Sivertsen et al., 2015). Sleep disturbance is common during the postpartum period and associated with higher levels of psychological distress and increased risk of developing postpartum psychiatric disorders (Tomfohr et al., 2015; Witkowska-Zimny et al., 2024). In both clinical and non-clinical populations, rigid sleep-related beliefs are associated with poorer sleep quality and may exacerbate sleep disturbance (Chang et al., 2018; Jin et al., 2018; Morin et al., 2007; Song et al., 2022). Although psychological flexibility has been shown to act as a predictor of sleep outcomes and protective factor in clinical and non-clinical populations (Ryan et al., 2025), the relationship between psychological flexibility and sleep in postpartum women is unexplored. Understanding the relationship between these factors can better inform therapeutic interventions for sleep quality for postpartum women and may have further effects on other maternal mental health outcomes.

Methods
Participants (N=135) were recruited using Prolific to complete an online survey conducted via Qualtrics. Eligibility criteria included women that had given birth within one year. Participants provided demographic information and completed a series of questionnaires which measured experiential avoidance and psychological inflexibility (Acceptance and Action Questionnaire – II; AAQ-I), sleep cognitions (Dysfunctional Beliefs and Attitudes about Sleep: Brief Version; DBAS-16), and subjective sleep quality (Pittsburgh Sleep Quality Index; PSQI).

Results
Multiple regression was performed to assess the association between experiential avoidance and psychological inflexibility, sleep cognitions, and subjective sleep quality. The overall model was significant in predicting subjective sleep quality, F(2, 135)=25.597, R2=0.275, p<.001. Specifically, greater experiential avoidance and psychological inflexibility significantly predicted worse subjective sleep quality (β = 0.200, t = 2.596, p=.010). Additionally, more dysfunctional sleep cognitions significantly predicted worse subjective sleep quality (β=0.426, t=5.514, p<.001).

Discussion
The current study finds that experiential avoidance, psychological inflexibility, and sleep cognitions, included as predictors, accounted for a statistically significant and moderate amount of variability in subjective sleep quality, with greater experiential avoidance, psychology inflexibility, and dysfunctional sleep cognitions positively correlated with worse subjective sleep quality. While factors that contribute to sleep disturbance in the postpartum period are multifactorial and, often, inseparable from new motherhood (i.e., infant sleep-wake cycles, nighttime feedings), our findings demonstrate that improving psychological flexibility, reducing experiential avoidance, and challenging dysfunctional sleep cognitions could potentially improve sleep quality in new mothers. Further research is needed to address potential sleep-related interventions in the perinatal population.