Winter babies crawl earlier than summer babies

Researchers from the University of Haifa in Israel found babies born in winter start crawling an average of five weeks before those born in the summer. Photo / 123RF

Babies born in winter start crawling earlier than those born in the summer, a study has found.

Israeli researchers say those born in the winter to spring months began crawling at an average of five weeks beforet their counterparts born in summer or autumn.

According to NHS information, babies should start crawling when they are between six and nine months old.

One theory is that winter babies might crawl earlier because they will usually start crawling in the summer months, when there is more daylight.

This means they are active for longer, they wear fewer layers and spend more time on the floor on their stomachs, the researchers said.

However they added the findings were specific to places such as Israel, where the home is very different between the summer and winter.

In countries where the home environment is similar all year round, due to things like central heating, the same effect is not observed, they qualified.

The study looked at 47 healthy babies with typical development, who were divided into two groups.

The first group had 16 babies born from June to November - the 'summer-fall' babies.

The second group had 31 babies born from December to May - the 'winter-spring' babies.

The babies were observed in their home when they were seven months old, with a second observation when they began to crawl.

Their parents were asked to record the stages in their babies' development before and between the observations.

Researchers used the Alberta Infant Motor Scale (AIMS), a highly-reliable measurement which looks at which position the baby is in.

The scale has four positions: prone (on the stomach), supine (on the back), sitting and standing.

The average age at which babies started crawling was 31 weeks.

Babies born in the winter - who started to crawl in the summer, started crawling at 30 weeks, while babies born in the summer - who started to crawl in the winter - started crawling at an average of 35 weeks.

The winter-spring babies had higher overall AIMS scores than the summer-fall babies, especially for movement in the prone position, which is the most meaningful for measuring crawling.

For the other positions on the AIMS scale there was no significant difference between the summer-fall or winter-spring babies, or between genders.

In their report, the researchers said: "The difference in crawling onset of four weeks constitutes 14 per cent of a seven-month-old's life - and is significant.

"The geographic location and the local climate where the study is conducted is important to understand the findings," they added.

A seasonal effect is found in places where the differences in the home environment between summer and winter are significant.

Studies done in Denver, Colorado and in Osaka, Japan found a seasonal effect that corresponds with the findings of the Haifa study.

However a study conducted in Alberta, Canada, where winters are long and cold on the one hand, but the home environment (because of winter heating) is very similar all year round, the seasonal effect was not observed.

"Although the winter in Israel is comparatively mild compared to other places in the world, it turns out that it nonetheless influences the motor development of babies because of the differences between summer and winter in Israel,"

The researchers said the findings could help make parents aware that they provide opportunities for their babies to move around and crawl in the winter months too.

"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.

Awareness of the seasonal effect is important so that parents will give their babies proper movement and development opportunities in the winter as well."

The research was conducted by Dr Osnat Atun-Einy of the University of Haifa's Department of Physical Therapy and Dr Dina Cohen, Mr Moran Samuel and Professor Anat Scher of the same University's Department of Counseling and Human Development.

- Daily Mail