Yawning in the womb

PLOS ONE

A study published last week shows that unborn babies yawn in the womb. From the Reuters story:

Growing into a fully formed human being is a long process, and 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 fetuses 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 fetuses 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 [Nov. 21], 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 fetuses is still unknown, but the findings suggest it may be linked to fetal development and could provide a further indication of the health of the unborn baby.

See below for video of an unborn child yawning.