As daylight savings time comes to an end, parents of young children may find themselves anxious about how the shift will disrupt their baby’s sleep schedules. Research indicates that the transition can be challenging for infants and toddlers, as their biological clocks require time to adjust, much like adults.
Dr. Pamela Douglas, a general practitioner and sleep researcher from Australia, emphasizes that even though mechanical clocks change immediately, the body’s internal clock takes longer to adapt. A study analyzing the sleep patterns of over 600 children following the spring clock change revealed that toddlers aged one to two years took an average of three days to return to their original bedtime, while infants under one experienced an adjustment period of about eight days. Additionally, the shift affected morning wake times, with some age groups losing an hour of sleep in the days following the transition. Notably, infants aged six to 11 months experienced a reduction in nighttime sleep of seven to 15 minutes, even four weeks post-adjustment.
Despite the slight reduction in nighttime sleep, experts from organizations such as the National Sleep Foundation stress that this loss is minimal compared to the total sleep recommended for infants, which ranges from 12 to 15 hours in a 24-hour period for those aged four to 11 months.
It is important to recognize that infants’ sleep patterns are inherently flexible. The notion of adhering to rigid sleep schedules is a relatively modern concept. In many pre-industrial societies, children often sleep with caregivers or drift off in their arms without a fixed bedtime routine. For example, a study of Maya families in Guatemala noted that babies would simply fall asleep when tired, alongside the rest of the family.
The impact of seasonal changes on sleep patterns also warrants attention. Research has shown that humans naturally tend to sleep longer in winter and shorter in summer. A study of foraging societies indicates that nighttime sleep duration can vary by nearly an hour between seasons, with winter sleep averaging 53 to 56 minutes longer. Although industrial societies experience less dramatic seasonal changes, they still feel some effects; for instance, a study of medical students in Berlin found that winter sleep duration increased by approximately 18 minutes compared to summer.
Moreover, studies have indicated that babies older than 10 weeks can also experience changes in sleep quality with the seasons. In autumn, eight-month-olds may enjoy less fragmented sleep and more slow-wave sleep compared to spring. In another study involving both eight-month-olds and 24-month-olds, researchers noted increased rhythmic brain activity during non-rapid eye movement sleep during the autumn months.
As parents navigate the upcoming clock change, understanding these sleep dynamics may help ease the transition for both themselves and their children.
