scientists have found that unborn babies not only hiccup, swallow and
stretch in the womb, they yawn too.
Researchers who studied 4D scans of 15 healthy foetuses also said they
think yawning is a developmental process which could potentially give
doctors a new way to check on a baby's health.
While some scientists have previously suggested that foetuses yawn,
others disagree and say it is nothing more than a developing baby
opening and stretching its mouth.
But writing in the journal PLOS ONE on Wednesday, British researchers
said their study was able to clearly distinguish yawning from
"non-yawn mouth opening" based on how long the mouth was open.
The researchers did this by using 4D video footage to examine all the
times when fetuses opened their mouths.
Nadja Reissland of Durham University's department of Psychology, who
led the study, said the function and importance of yawning in foetuses
is still unknown, but the findings suggest it may be linked to foetal
development and could provide a further indication of the health of
the unborn baby.
"Unlike us, foetuses do not yawn contagiously, nor do they yawn
because they are sleepy," she said. "Instead, the frequency of yawning
in the womb may be linked to the maturing of the brain early in
gestation."
The study was carried out on eight female and seven male foetuses from
24 to 36 weeks gestation. The researchers found that yawning declined
from 28 weeks and that there was no significant difference in how
often boys and girls yawned. [Reuters]