He can hardly have been burning the candle at both ends – but perhaps he’s tired out from all that growing.
This remarkable picture shows a baby yawning in the womb.
It is one of dozens produced by Durham University researchers who were fascinated by whether foetuses yawn and, if so, why.
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Scientists estimate that babies yawn six times an hour in the womb
Stretch! Yawning in the womb could strengthen the jaw, say scientists
To find out, they gave 15 mothers-to-be 4D ultrasound scans four times during their pregnancy. The last was done at 36 weeks, just a few weeks before the eight girls and seven boys were born.
Rather then the grainy ‘flat’ images produced by the 2D scanners usually used by the NHS, a 4D machine stitches together pictures taken from a variety of angles to create clear three-dimensional images.
These are then recorded on video – the fourth dimension. Researchers painstakingly analysed these highly detailed videos frame by frame to see how the foetuses moved their mouths.
Wide open: Yawning may be a sign of brain development or a quick and easy way of cooling down the brain
Some academics believe that rather than yawning, the babies are simply opening and closing their mouths.
But researcher Nadja Reissland said the scans provided clear evidence that they yawn as well.
On some occasions, a baby would slowly open their mouth, before quickly snapping it shut – characteristics of a yawn.
The analysis revealed that the youngest babies yawned the most, but there was no difference between the sexes.
Dr Reissland calculated that if she had been able to monitor the babies for longer, she would have caught them yawning an average of six times an hour.
She was not sure why they yawned, but said it was unlikely to be because they were tired. Instead, she believes that the long, slow stretch could help the development of brain regions involved in the movement of the jaw.
If yawning is a sign of brain development, Dr Reissland believes that it could one day be added to the indicators doctors use to determine whether a foetus is developing normally.
Her findings were published in the journal PLoS ONE.
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