Effectiveness and Mechanisms of a Digital Mindfulness-Based Intervention for Subthreshold to Clinical Insomnia Symptoms in Pregnant Women: Randomized Controlled Trial.

backgroundPrenatal insomnia symptoms are prevalent, debilitating, and largely untreated; yet, there is a lack of empirically supported and accessible interventions. Mindfulness-based interventions have been theoretically hypothesized to alleviate insomnia symptoms by counteracting adverse sleep-related cognitive and behavioral processes, although few studies have tested them.

objectiveThis study aimed to examine the effectiveness and potential mechanisms of a digital mindfulness-based intervention targeted at prenatal insomnia (dMBI-PI) in reducing insomnia symptoms.

methodsA single-blind randomized controlled trial was conducted from October 2021 to February 2023. A total of 160 eligible pregnant women (mean age 30.54, SD 3.86 years) with subthreshold to clinical insomnia symptoms (corresponding to a score of ≥8 on the Insomnia Severity Index) were recruited from obstetrics clinics and then randomized 1:1 into the intervention group (the 6-week dMBI-PI plus standardized care) or the control group (standardized care). The primary outcome was the insomnia symptoms assessed at baseline, immediately after the intervention, 2 months after the intervention (approximately the third trimester), and 42 days post partum. The secondary outcomes included insomnia remission rates and reliable change rates, sleep onset latency, wake after sleep onset, total sleep time, sleep efficiency, sleep quality, fatigue symptoms, daytime sleepiness, anxiety, and depressive symptoms. The hypothesized mediators included sleep-specific rumination, sleep-specific worry, presleep arousal, sleep-related attentional bias, and maladaptive behaviors. All outcomes were self-assessed through web-based questionnaires. Linear mixed model analysis was conducted to examine the dMBI-PI's effects.

resultsCompared with the control group, the intervention group had significantly greater improvements in insomnia symptoms from baseline to the end of the intervention (mean between-group difference -2.02, 95% CI -3.42 to -0.62; P=.005; Cohen d=0.46, 95% CI 0.01-0.92) and from baseline to the third trimester (mean between-group difference -2.02, 95% CI -3.42 to -0.61; P=.005; Cohen d=0.46, 95% CI 0.01-0.92), but a beneficial effect was not observed post partum. The intervention group had a significantly increased likelihood of achieving insomnia remission or reliable change at the third trimester; however, we did not observe significant between-group differences in the changes in most secondary outcomes. The changes in adverse cognitive and behavioral processes (mainly sleep-specific worry and presleep arousal) significantly mediated the dMBI-PI's effect on prenatal insomnia symptoms.

conclusionsThe dMBIs showed significant short-term benefits for prenatal insomnia symptoms by mitigating sleep-specific worry and presleep arousal and may therefore hold promise as a first-step, pragmatic, and accessible option for pregnant women at risk of insomnia.

trial registrationChinese Clinical Trial Register (ChiCTR) ChiCTR2100052269; https://tinyurl.com/4bb8f7ah.