Differentiating perinatal Insomnia Disorder and sleep disruption: a longitudinal study from pregnancy to 2 years postpartum

STUDY OBJECTIVES: Insomnia Disorder diagnoses require persistent sleep complaints despite "adequate sleep opportunity." Significant Perinatal Sleep Disruption makes this diagnosis challenging. This longitudinal study distinguished between Insomnia Disorder and Perinatal Sleep Disruption and their sleep and mental health correlates. METHODS: One hundred sixty-three nulliparous females (age M ± SD = 33.35 ± 3.42) participating in a randomized controlled trial repeated the Insomnia Disorder module of the Duke Structured Interview for Sleep Disorders and Patient-Reported Outcome Measurement Information System measures for sleep and mental health at 30- and 35-weeks' gestation, and 1.5, 3, 6, 12, and 24 months postpartum (944 interviews, 1009 questionnaires completed). We compared clinical features when Diagnostic and Statistical Manual of Mental Disorders (DSM-5) Insomnia Disorder criteria (without the Duration criterion) were: (1) met (Insomnia Disorder), (2) not met only because of the sleep opportunity criteria (Perinatal Sleep Disruption), and (3) not met due to other criteria (Low Complaint). RESULTS: Proportions of Insomnia Disorder were 16.0% and 19.8% during early and late third trimester, and ranged 5.3%-11.7% postpartum. If the sleep opportunity criteria were not considered, rates of Insomnia would be 2-4 times higher (21.4%-40.4%) across time-points. Mixed-effects models adjusting for covariates showed that compared to Low Complaint, both Insomnia Disorder and Perinatal Sleep Disruption scored significantly higher on insomnia and sleep disturbance scales, sleep effort, and sleep-related impairments (p values < .01), but depression and anxiety were comparable (p values > .12). CONCLUSION: Assessing sleep complaints without considering sleep opportunities can result in over-diagnosis of Insomnia Disorder in the perinatal periods. Insomnia Disorder and Perinatal Sleep Disruption were both associated with adverse sleep and mood outcomes, and need to be carefully differentiated and appropriately addressed. Clinical Trial Registration: The SEED Project (Sleep, Eat, Emotions, and Development): A randomized controlled pilot study of a perinatal sleep intervention on sleep and wellbeing in mothers and infants. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371634, Australian New Zealand Clinical Trials Registry: ACTRN12616001462471.