New research in Finland has revealed that seasonal changes in daylight do affect the quality of sleep that babies get.
In her doctoral study, clinical neurophysiology specialist Anja Kärki found that seasonal daylight changes play a role when studying the sleep patterns of young children.
The effects of daylight hours on people's sleep have been widely studied, but these effects on babies have not been examined very much at all, Kärki noted in her dissertation's abstract.
"There is a scarcity of evidence on the effects of season on sleep during early childhood, and most of the previous data are not based on the gold standard of sleep evaluation, polysomnography," she wrote.
Polysomnography is a diagnostic tool used to examine sleep that measures a subject's brain waves, blood oxygen levels, heart and breathing rates.
Kärki is to present her dissertation, Associations between Finnish Seasons and Sleep in Early Childhood at Tampere University on 15 December.
"Seasons significantly affect the amount of natural light in Finland," she said.
Therefore, according to the researcher, the results of previous sleep studies carried out in other parts of the world do not necessarily apply to conditions in the Nordic country.
Similar studies have shown that adults' sleep rhythms can be delayed in the darker time of year while grown-ups' tend to get less sleep during the bright summertime months.
Kärki's research involved monitoring children's sleep at one month, eight months and two years of age.
Infants need light-dark schedule
She found that infants seem to be more sensitive to seasonal light changes than their older toddler-aged counterparts.
"Just as in adults, the bright season may also shorten infants' sleep durations. However, their sleep does not seem to suffer during the bright months of summer," she explained.
On the other hand, the rapid increase of light in spring does weaken the quality of sleep that eight-month-olds get, according to the findings.
Kärki's research also examined the effects that the springtime daylight saving clock change had on eight-month-olds. The sudden schedule changes appears to reduce their sleep quality.
"There is no rational reason for changing the clocks, and I have never met a sleep researcher who supports the practice," she said.
Based on the results, it is recommended for a baby in the first year of life to follow a regular light-dark schedule — along with other regular daily patterns.
It is recommended to emphasise light exposure and more activities in the morning and day, while it is a good idea to calm down and reduce light exposure in the evening.
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