Preventing postpartum insomnia: findings from a three-arm randomized-controlled trial of cognitive behavioral therapy for insomnia, a responsive bassinet, and sleep hygiene

Abstract

Study objectives: Insomnia symptoms are common during the perinatal period and are linked to adverse outcomes. This single-blind three-arm randomized-controlled trial examined whether two interventions targeting different mechanisms prevent postpartum insomnia.

Methods: Participants were nulliparous females 26-32 weeks gestation with Insomnia Severity Index (ISI) scores ≥ 8, recruited in Australia and randomized 1:1:1 to: (1) a responsive bassinet (RB) designed to support infant sleep and reduce maternal sleep disruption until 6 months postpartum, (2) therapist-assisted cognitive behavioral therapy for insomnia (CBT-I) delivered during pregnancy and postpartum, or (3) a sleep hygiene booklet (control; CTRL). Outcomes were assessed at baseline (T1), 35-36 weeks gestation (T2), and 2, 6, and 12 months postpartum (T3-T5). The primary outcome was ISI scores averaged T3-T5. Primary analyses were regressions controlling for baseline outcomes.

Results: One hundred and twenty-seven participants (age M ± SD = 32.62 ± 3.49) were randomized (RB = 44, CBT-I = 42, CTRL = 41). Both interventions were feasible and well-accepted, with few related adverse events reported. Compared to CTRL, the average ISI across T3-T5 was lower for CBT-I (p = .014, effect size [ES] = 0.56, medium) but not RB (p = .270, ES = 0.25, small). Exploratory findings on maternal insomnia diagnosis, sleep disturbance, sleep-related impairment, beliefs and attitudes about sleep, depression, anxiety, as well as infant sleep outcomes were also presented.

Conclusions: CBT-I but not RB reduced prenatal insomnia (very large effect) and prevented postpartum insomnia (medium effect). Further research is needed to examine the effects of both CBT-I and RB on other outcomes such as sleep-related well-being, postpartum depression, and maternal postpartum sleep duration.

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.

Keywords: cognitive behavioral therapy; insomnia; pediatrics—infants; postpartum depression; pregnancy; women’s health.

Graphical Abstract

Figure 1.

CONSORT diagram of participant flow. ISI, Insomnia Severity Index; CBT-I, Cognitive Behavioral Therapy for Insomnia; T1 = 26–32 weeks pregnancy; T2 = 35–36 weeks pregnancy; T3 = 2 months postpartum; T4 = 6 months postpartum; T5 = 12 months postpartum.

Figure 2.

Multiple regression analyses adjusting for baseline outcomes for Insomnia Severity Index scores. Unstandardized estimates and 95% confidence intervals are shown. The primary outcome is average ISI scores across T3, T4, and T5 (represented in gray dashed line for CTRL, gray solid line for RB, and black solid line for CBT-I); CBT-I condition reported lower average ISI during the postpartum period compared to the CTRL (2.01 point ISI difference; p = .014, ES = 0.56); differences in the average ISI scores across T3-T5 were small between the RB and CTRL (0.87 point ISI difference; p = .270, ES = 0.25). See Supplementary Table S1 for numeric summary. ES, effect size; CTRL, control condition; RB, responsive bassinet condition; CBTI, Cognitive Behavioral Therapy for Insomnia condition.