A randomized controlled trial on the effects of blue-blocking glasses compared to partial blue-blockers on sleep outcomes in the third trimester of pregnancy.

Randi Liset,Tone E G Henriksen,Ståle Pallesen,Roy M Nilsen,Janne Grønli,Roger E Henriksen

doi:10.1371/journal.pone.0262799

Abstract

ObjectiveSleep disturbances are common in pregnancy. Blocking blue light has been shown to improve sleep and may be a suitable intervention for sleep problems during pregnancy. The present study investigated the effects of blue light blocking in the evening and during nocturnal awakenings among pregnant women on primary sleep outcomes in terms of total sleep time, sleep efficiency and mid-point of sleep.MethodsIn a double-blind randomized controlled trial, 60 healthy nulliparous pregnant women in the beginning of the third trimester were included. They were randomized, using a random number generator, either to a blue-blocking glass intervention (n = 30) or to a control glass condition constituting partial blue-blocking effect (n = 30). Baseline data were recorded for one week and outcomes were recorded in the last of two intervention/control weeks. Sleep was measured by actigraphy, sleep diaries, the Bergen Insomnia Scale, the Karolinska Sleepiness Scale and the Pre-Sleep Arousal Scale.ResultsThe results on the primary outcomes showed no significant mean difference between the groups at posttreatment, neither when assessed with sleep diary; total sleep time (difference = .78[min], 95%CI = -19.7, 21.3), midpoint of sleep (difference = -8.9[min], 95%CI = -23.7, 5.9), sleep efficiency (difference = -.06[%], 95%CI = -1.9, 1.8) and daytime functioning (difference = -.05[score points], 95%CI = -.33, .22), nor by actigraphy; total sleep time (difference = 13.0[min], 95%CI = -9.5, 35.5), midpoint of sleep (difference = 2.1[min], 95%CI = -11.6, 15.8) and sleep efficiency (difference = 1.7[%], 95%CI = -.4, 3.7). On the secondary outcomes, the Bergen Insomnia Scale, the Karolinska Sleepiness Scale and the Pre-Sleep Arousal Scale the blue-blocking glasses no statistically significant difference between the groups were found. Transient side-effects were reported in both groups (n = 3).ConclusionsThe use of blue-blocking glasses compared to partially blue-blocking glasses in a group of healthy pregnant participants did not show statistically significant effects on sleep outcomes. Research on the effects of blue-blocking glasses for pregnant women with sleep-problems or circadian disturbances is warranted.Trial registrationThe trial is registered at ClinicalTrials.gov (NCT03114072).

Highlights

Sleep was measured by actigraphy, sleep diaries, the Bergen Insomnia Scale, the Karolinska Sleepiness Scale and the Pre-Sleep Arousal Scale
The use of blue-blocking glasses compared to partially blue-blocking glasses in a group of healthy pregnant participants did not show statistically significant effects on sleep outcomes
A decrease in insomnia score for the BB-group and an increase for the control group posttreatment were shown on the Bergen Insomnia Scale (BIS) this was not statistically significant, even the control group improved significant within group

Summary

Introduction

Pregnant women typically experience increased need for sleep in the first trimester and increased sleep disturbances during the third trimester [1]. By gestational week 40, as many as 75–98% report multiple nocturnal awakenings [2,3,4,5]. Insomnia is the most frequent sleep disorder in pregnancy reported by 62% of pregnant women, which is significantly higher than found in the general population (10–15%) [1, 6, 7]. Insomnia manifests as difficulties falling asleep, maintaining sleep, or early morning awakenings, occurring for at least three nights per week [8]. Several hormonal and mechanical influences can cause insomnia during pregnancy, including nocturia (a frequent need to rise and urinate at night), dyspnea (shortness of breath), nasal congestion, muscular aches and pelvic pains, fetal activity, leg cramps as well as reflux [1]

Methods

Results

Conclusion