Preventing postpartum insomnia by targeting maternal versus infant sleep: A protocol for a randomized controlled trial (the Study for Mother-Infant Sleep "sMILE")

Symptoms of insomnia are common during the perinatal periods and are linked to adverse parent/infant outcomes. Theories on insomnia development (e.g. 3P model) suggest that significant sleep disruption (e.g. nighttime infant care) can precipitate, while unhelpful sleep-related cognitions/behaviors can perpetuate parental insomnia symptoms. This study aims to examine how two interventions, one addressing infant sleep as the precipitator, the other targeting maternal sleep-related cognitions/behaviors as the perpetuator, might prevent postpartum insomnia. Participants are 114 nulliparous females 26 to 32 weeks gestation, with self-reported insomnia symptoms (Insomnia Severity Index scores ≥ 8). Participants are randomized to one of three conditions and receive: (1) a "responsive bassinet"used until 6 months postpartum, designed to boost/consolidate infant sleep and target infant sleep as a precipitator of insomnia, (2) therapist-Assisted cognitive behavioral therapy for insomnia, addressing unhelpful sleep-related cognitions/behaviors as perpetuators of insomnia, or (3) a sleep hygiene booklet (control condition). The primary outcome is maternal insomnia symptoms. Secondary outcomes include maternal sleep duration/quality, mental health (e.g. depression, anxiety), and wellbeing-related variables (e.g. sleep-related impairment). Outcomes are assessed using validated instruments at 26-32 and 35-36 weeks' gestation, and 2, 6, and 12 months postpartum. This study adopts an early-intervention approach and longitudinally compares two distinct approaches to prevent postpartum insomnia in an at-risk population. If interventions are efficacious, findings will demonstrate how interventions targeting different mechanisms mitigate insomnia symptoms in perinatal populations. This will provide empirical evidence for future development of multi-component sleep intervention to improve mother-infant wellbeing. Clinical Trial Registration: The Study for Mother-Infant Sleep (The SMILE Project): reducing postpartum insomnia using an infant sleep intervention and a maternal sleep intervention in first-Time mothers. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377927, Australian New Zealand Clinical Trials Registry: ACTRN12619001166167.