Nightly Light Exposure in Pregnancy: Blue-blocking Glasses as an Intervention to Ease Sleep Disturbances and to Improve Mood
Nightly Light Exposure in Pregnancy: Blue-blocking Glasses as an Intervention to Ease Sleep Disturbances and to Improve Mood
Sleep disturbances are common in pregnancy, and the incidence increases during the third trimester. Light and specially the blue wavelengths of light, is affecting sleep and the circadian rhythm. The main aim of this randomized controlled study is to investigate the effect of Blue-blocking glasses (BB-glasses) used in the evening and night on sleep and mood in pregnant women in the third trimester. The outcome measures assess sleep variables, alertness, melatonin level, sleepiness (subjectively), mood and symptoms of anxiety and depression. In addition we want to measure the pregnancy related sleep problems, alcohol intake, physical activity and perceives stress in the study population, and the association with daily/nightly light exposure.
Several hormonal and mechanical influences can cause insomnia in pregnancy, and insomnia has been reported by 62% of pregnant women, a number that is significantly higher than found in the general population (10-15%). Disrupted sleep among pregnant women also includes nocturia (a frequent need to get up and urinate at night), dyspnea (shortness of breath), nasal congestion, muscular aches and pelvic pains, fetal activity, leg cramps as well as reflux.
Artificial light in the evening and during the night increases alertness, disturbs sleep, shifts the timing of the circadian clock and impairs the brains' restorative slow waves during deep sleep. Recent studies have however shown that use of BB-glasses in the evening improves sleep quality (subjectively reported) among persons with insomnia, and prevent alertness caused by blue-light emitting screens which are part of devices such as smart-phones and tablets.
This project will contribute with new knowledge on how filtering nightly light exposure in pregnant women in their third trimester affects their sleep and mood. Importantly, the project initiates new research on a potential non-pharmacological treatment of sleep disturbances by blocking blue wavelengths of light in the evening and during nocturnal awakenings. Blue light is known to increase alertness through a recently described retinal receptor; the intrinsically photoresponsive retinal ganglion cell (IpRGC), specialized for detecting daytime light signal. This project is highly innovative and may have significant practical implications Due to the variety of aims and outcome measures, we plan to present the outcomes in separate articles.
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