Why sticking with the program could change how well it works
Digital CBT-I is a structured, skills-based treatment: it typically asks people to change sleep habits, keep sleep diaries, and adjust time in bed over several weeks. Because the active ingredients are behaviors the person carries out, not a passive pill, the amount of the program someone actually completes is a plausible driver of benefit. The meta-analysis of digital CBT-I explicitly analyzed treatment adherence and compared outcomes between adherent and non-adherent groups [5], which is the kind of design needed to ask whether doing more of the program tracks with better results.
That said, the meta-analysis did not include pregnant or postpartum participants [5], so its adherence–outcome comparison describes general adult users rather than the perinatal group the question asks about. The perinatal CBT-I study measured adherence and perceived usefulness of intervention components and linked them to sleep outcomes [4], which is the most direct evidence available here for pregnancy and postpartum—but it is a single study, so the perinatal picture rests on limited data.
Pregnancy and postpartum add practical barriers to finishing a program
Pregnancy and the postpartum period involve major sleep changes, and the reviewed digital CBT-I work for these periods emphasizes adaptations rather than a one-size-fits-all course. One review notes that CBT-I during pregnancy may benefit from a session module that prepares expectant mothers for postpartum [1], and another review describes content addressing the realities of pregnancy and postpartum plus guidance on managing infant sleep [2]. Those adaptations are framed as ways to make the program fit the perinatal situation, which is consistent with the idea that engagement—not just raw efficacy—is a live issue in this group.
However, neither of those reviews provides explicit adherence or engagement data [1][2]. So while they support the general efficacy of digital CBT-I and describe perinatal tailoring, they cannot tell us how much adherence varies in pregnancy and postpartum or how strongly it tracks with sleep improvement. The direct adherence–outcome analysis in the perinatal CBT-I study [4] is therefore the key piece, and it should be read as an early, focused finding rather than a settled answer.
What we can and cannot conclude about the perinatal group
Putting the pieces together: in general adult users, adherence to digital CBT-I was analyzed and adherent versus non-adherent outcomes were compared [5], supporting the practical answer that sticking with the program is linked to how well it works. In pregnancy and postpartum, a study measured adherence and perceived usefulness of components and their associations with sleep outcomes [4], which points in the same direction for this group. But the perinatal reviews that discuss digital CBT-I efficacy and adaptations do not report adherence or engagement measures [1][2], so the size of the adherence effect in pregnancy and postpartum—and whether it differs from the general population—remains uncertain.
One nearby piece of evidence is easy to misread: a digital biopsychosocial cognitive-behavioural intervention for pregnant women did include an adherence analysis and targeted mental health and wellbeing during pregnancy and postpartum [3]. But that intervention was not focused on insomnia, so it speaks to engagement with a digital psychological program in pregnancy, not to digital CBT-I for sleep. It should not be used to fill the adherence gap for CBT-I specifically.
What this means if you are considering digital CBT-I in pregnancy or postpartum
The reasonable reading is that completing more of a digital CBT-I program is likely to matter for sleep benefit, based on the general adult adherence comparison [5] and the perinatal adherence–outcome analysis [4]. For pregnancy and postpartum specifically, the evidence supports trying a program that includes preparation for the postpartum period and guidance on infant sleep [1][2], since those adaptations are designed around the barriers this group faces. What the current evidence does not yet establish is how large the adherence effect is in perinatal users or whether it is meaningfully different from other adults—those reviews simply do not report the engagement data needed to answer that [1][2].
Sources used in this answer
CBT‐I protocols across the female lifespan
Reviews digital CBT-I across the female lifespan, including pregnancy and postpartum, and suggests CBT-I in pregnancy may benefit from a module preparing expectant mothers for postpartum, but reports no explicit adherence or engagement data.
Population-Specific Applications of Digital CBT-I: Evidence, Adaptations, and Emerging Directions
Reviews digital CBT-I across populations including perinatal groups, describing efficacy and adaptations such as content on pregnancy, postpartum, and infant sleep management, but does not detail adherence or engagement measures.
Effectiveness of an online biopsychosocial cognitive-behavioural preventive intervention to improve wellbeing and mental health during pregnancy …
Tests a digital biopsychosocial cognitive-behavioural preventive intervention with an adherence analysis in healthy pregnant women to improve wellbeing and mental health during pregnancy and postpartum, but the intervention is not focused on insomnia.
Cognitive Behavioral Therapy for Perinatal Insomnia: Exploring Adherence, Perceived Usefulness of Intervention Components, and their Associations with Sleep …
Examines CBT-I for insomnia in a perinatal population, analyzing adherence and perceived usefulness of intervention components and their associations with sleep outcomes.
Digital cognitive behavioral therapy for insomnia on depression and anxiety: a systematic review and meta-analysis
Meta-analysis of digital CBT-I for insomnia, depression, and anxiety that analyzed treatment adherence and compared outcomes between adherent and non-adherent groups, but did not include pregnant or postpartum participants.