225 Sleep Timing and Chronotype in Mothers: Longitudinal Changes and Associations with Wellbeing from Pregnancy to 2 Years Postpartum

Introduction

Women experience significant changes to sleep during perinatal periods. Existing research focuses on sleep duration and quality, but not sleep timing or chronotype (i.e., preferred timing for activity and sleep). This study investigated change trajectories of sleep timing and chronotype from late pregnancy to two years postpartum, and examined longitudinal associations between chronotype and insomnia, sleep-related daytime impairment, and mood.

Methods

Data were from a 2-arm randomized controlled trial testing behavioral sleep and diet interventions. A community sample of nulliparous women without severe sleep/mental health conditions participated. Women self-reported bedtime, risetime, chronotype (reduced Morningness-Eveningness Questionnaire), Insomnia Severity Index, and PROMIS Depression, Anxiety, and Sleep-Related Impairment over 7 time points: 30 and 35 weeks’ gestation, and postpartum months 1.5, 3, 6, 12 and 24.

Results

163 women (mean age 33.35 ± 3.42 years) took part. Mixed effects models controlling for age and group allocation showed that both bed- and risetimes became progressively earlier over time by approximately 20-30 minutes on average (p < .001); chronotype also shifted progressively towards morningness (p < .01). After controlling for covariates (sleep duration and efficiency, mental health history, social support, age, group allocation), greater morningness was significantly associated with lower symptoms of insomnia and sleep-related impairment over time (p-values < .001); longitudinal associations between chronotype and symptoms of depression and anxiety were non-significant (p-values > .65).

Conclusion

This is one of the first studies to examine longitudinal changes in sleep timing and chronotype from pregnancy to two years postpartum. Sleep timing and chronotype became progressively earlier over the first two postpartum years. The magnitude of changes is beyond what is expected with increasing age. Greater morningness was associated with lower sleep complaints and sleep-related daytime impairment during the postpartum period. The mechanisms underlying these associations require further research.

Support (if any)

Australasian Sleep Association, Monash University, Australian Government RTP Scholarship and National Health and Medical Research Council.

340 Improving maternal sleep via cognitive behavioral intervention: A randomised controlled trial from pregnancy to 2 years postpartum

Introduction

Maternal sleep disturbance is common during pregnancy and postpartum periods. This study evaluated the feasibility and efficacy of a scalable cognitive behavioural therapy (CBT) sleep intervention tailored for these periods.

Methods

This is a two-arm, parallel-group, single-blind, superiority randomised controlled trial. Nulliparous women without major medical/psychiatric conditions were randomised 1:1 to CBT or active control of equal frequency/duration. All participants received a 1-hr telephone session and automated multimedia emails from the 3rd trimester until 6 months postpartum. Outcomes were assessed with validated instruments at gestation weeks 30 (baseline) and 35 (pregnancy endpoint), and postpartum months 1.5, 3, 6 (postpartum endpoint), 12, and 24.

Results

163 eligible participants (age M +/- SD = 33.35 +/- 3.42) were randomised. The CBT intervention was well accepted, with no reported adverse effect. Intention-to-treat analyses showed that compared to active control, receiving CBT was associated with lower insomnia severity and sleep disturbance (two primary outcomes), and lower sleep-related impairment at the pregnancy endpoint (p-values ≤ .001), as well as at 24 months postpartum (p ranges .012-.052). Group differences across the first postpartum year were nonsignificant. Women with elevated insomnia symptoms at baseline benefitted substantially more from CBT (vs control), including having significantly lower insomnia symptoms throughout the first postpartum year. Group differences in symptoms of depression or anxiety were nonsignificant.

Conclusion

A scalable CBT sleep intervention is efficacious in buffering against sleep disturbance during pregnancy, with long-term benefits to maternal sleep, especially for women with sleep complaints during pregnancy. The intervention holds promise for implementation into routine perinatal care.

Support (if any)

Data collection was supported by Rob Pierce Grant-in-Aid and Helen Bearpark Scholarship from Australasian Sleep Association, Strategic Grant Scheme from Monash University, and the Royal Women’s Hospital Foundation. Intervention materials were adapted from those developed via a National Institute of Health R01 grant (NR013662). Bei (APP1140299) and Wiley (APP1178487) are supported by National Health and Medical Research Council Fellowships, and Pinnington, Quin, Shen by Australian Postgraduate Awards by Department of Education and Training. The funder of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.