Infants who have started crawling wake up more often at night compared to the period before the crawling, reveals a new study by Dr. Dina Cohen of the University of Haifa's Department of Counseling and Human Development.
The doctoral study, conducted under the supervision of Prof. Anat Scher, observed 28 healthy babies who were developing normally, examining them once every two to three weeks. Their motor development and sleeping habits were monitored from age 4-5 months and continued until age 11 months. Their sleep patterns were measured by a device called an ActiGraph that provides objective evaluations of sleep patterns, taken together with parental reports from diaries and questionnaires. The infants' crawling development and progress was observed and videoed by the researcher.
The study showed that the average age for the babies to begin crawling was 7 months, and that this was accompanied by an increase in the number of times they woke up at night, from an average of 1.55 times per night to 1.98 times (based on the ActiGraph measurements). The incidents of wakefulness also lasted longer, about 10 minutes on average, as per parental reports.
The study also found that the scope and complexity of the changes – which included waking more frequently and moving around a lot during asleep – were more pronounced among those who started crawling earlier. By contrast, those who started to crawl later demonstrated only one change: waking up more frequently.
The good news for parents: Within three months from the day crawling begins, the baby will generally return to the sleep patterns from before acquiring the new motor skill.
According to Dr. Cohen, there are a number of reasons why starting to crawl and wakefulness could be linked. "It is possible that crawling, which involves a vast range of changes and psychological reorganization in the babies' development, increases their level of arousal, influences their ability to regulate themselves and causes a period of temporary instability that expresses itself in waking up more frequently," she suggests.
Increased restlessness in babies who crawl early, she says, could be attributed to the baby's expressing fears of being physically distanced from the mother before fully developing the psychological mechanisms to cope with separation effectively. "This fear is likely to be expressed in sleep interruptions during the night," she explained.
"With ongoing monitoring of babies' development, we can demonstrate that the increased awakenings are a temporary short-term phenomenon, which occurs as part of a wider process of the baby's gradually improving ability to regulate states of sleep and wakefulness," adds Dr. Cohen.