Babies born in winter start crawling earlier compared to the babies born in summer season, a new study has revealed.
The research by University of Haifa showed that season of a baby's birth influenced its motor development during its first year of life.
For the study, 47 healthy babies with typical development patterns were divided into two groups. The first group comprised "summer-fall" babies, 16 babies born from June to November, and the second, "winter-spring" babies, 31 babies born from December to May. The study consisted of motor observations in the babies' homes when there were seven months old, and a follow-up session when they began to crawl. Parents were asked to record the stages in their babies' development before and between the observations.
The study used the Alberta Infant Motor Scale (AIMS), an observational assessment with high reliability, to track the babies' development. The scale related to four positions: Prone (on the stomach), supine (on the back), sitting, and standing. The average age at which the babies started crawling was 31 weeks. But while the babies born in the winter (who started to crawl in the summer) started to crawl at an average 30 weeks, those born in the summer (who started to crawl in the winter) began crawling at an average of 35 weeks, with no differences noted between the boys or the girls or in the initial style of crawling (belly crawling or using hands and knees).
The overall AIMS score was higher for those babies born in the winter, and the score for movement in the prone position, the scale most meaningful in connection with crawling was, significantly higher for the babies in the winter group. By contrast, there was no significant difference in the scores for the supine position, sitting, or standing between the two groups. According to the researchers, the findings strengthen the assumption that there is a window of opportunity for starting to crawl and stress the effect of the season on the start of crawling.
The researchers added that the geographic location and the local climate where the study was conducted were important to understand the findings. Although the winter in Israel was comparatively mild compared to other places in the world, it turned out that it nonetheless influenced the motor development of babies because of the differences between summer and winter in Israel.
The season influences the babies' experiences in a number of ways, including layers of clothing that are worn; the opportunities babies are given to spend on the floor on their stomachs, and the hours of activity and daylight, said the researchers.