Fetuses yawn in the womb, according to new research

November 21, 2012, Durham University
Ultrasound pictures show difference in fetus yawning and other mouth openings
The ultrasound image shows mouth opening at 27.5 weeks gestation. Credit: Citation: Reissland N, Francis B, Mason J (2012) Development of Fetal Yawn Compared with Non-Yawn Mouth Openings from 24–36 Weeks Gestation. PLoS ONE 7(11): e50569. doi:10.1371/journal.pone.0050569

The 4D scans of 15 healthy fetuses, by Durham and Lancaster Universities, also suggest that yawning is a developmental process which could potentially give doctors another index of a fetus' health.

The study is published today (Nov 21) in the prestigious international academic journal, PLOS ONE. It was funded by the Economic and Social Research Council (ESRC).

While some researchers have suggested that fetuses yawn, others have disagreed and claim it is simple mouth opening.

But the new research clearly distinguished '' from 'non-yawn mouth opening' based on the duration of mouth opening. The researchers did this by using the 4D to closely examine all events where a mouth stretch occurred in the fetus.

Using their newly developed criteria, the research team found that over half of the mouth openings observed in the study were classed as yawns.

The study was carried out on eight female and seven male from 24 to 36 weeks gestation. The researchers found that yawning declined from 28 weeks and that there was no significant difference between boys and girls in yawning frequency.

Although the function and importance of yawning is still unknown, the study findings suggest that yawning could be linked to , and as such could provide a further medical indication of the health of the .

Ultrasound pictures show difference in fetus yawning and other mouth openings
This is an ultrasound showing yawn at 27.5 weeks gestation. Credit: Citation: Reissland N, Francis B, Mason J (2012) Development of Fetal Yawn Compared with Non-Yawn Mouth Openings from 24–36 Weeks Gestation. PLoS ONE 7(11): e50569. doi:10.1371/journal.pone.0050569

Lead researcher, Dr Nadja Reissland, of Durham University's Department of Psychology, said: "The results of this study demonstrate that yawning can be observed in healthy fetuses and extends previous work on fetal yawning. Our shows that yawning declines with increasing fetal age.

"Unlike us, fetuses do not yawn contagiously, nor do they yawn because they are sleepy. Instead, the frequency of yawning in the womb may be linked to the maturing of the brain early in gestation.

"Given that the frequency of yawning in our sample of healthy declined from 28 weeks to 36 weeks gestation, it seems to suggest that yawning and simple mouth opening have this maturational function early in gestation."

She added that yawning could be related to central nervous system maturation but further research involving mother and fetus would be required to examine this theory.

Explore further: More than a sign of sleepiness, yawning may cool the brain

More information: Reissland N, Francis B, Mason J (2012) Development of Fetal Yawn Compared with Non-Yawn Mouth Openings from 24 Weeks Gestation. PLoS ONE 7(11): e50569. dx.plos.org/10.1371/journal.pone.0050569

Related Stories

More than a sign of sleepiness, yawning may cool the brain

September 19, 2011
Though considered a mark of boredom or fatigue, yawning might also be a trait of the hot-headed. Literally.

Recommended for you

Researchers identify blood biomarkers that may help diagnose, confirm concussions

April 20, 2018
Researchers from the University of California, Irvine, Georgetown University and the University of Rochester have found that specific small molecules in blood plasma may be useful in determining whether someone has sustained ...

DOR protein deficiency favors the development of obesity

April 20, 2018
Obesity is a world health problem. Excessive accumulation of fat tissue (adipose tissue) increases the risk of cardiovascular disease, hypertension, diabetes and some types of cancer. However, some obese individuals are less ...

Stem-cell technology aids 3-D printed cartilage repair

April 20, 2018
Novel stem-cell technology developed at Swinburne will be used to grow the massive number of stem cells required for a new hand-held 3-D printer that will enable surgeons to create patient-specific bone and cartilage.

Enduring cold temperatures alters fat cell epigenetics

April 19, 2018
A new study in fat cells has revealed a molecular mechanism that controls how lifestyle choices and the external environment affect gene expression. This mechanism includes potential targets for next-generation drug discovery ...

Defect in debilitating neurodegenerative disease reversed in mouse nerves

April 19, 2018
Scientists have developed a new drug compound that shows promise as a future treatment for Charcot-Marie-Tooth disease, an inherited, often painful neurodegenerative condition that affects nerves in the hands, arms, feet ...

Molecule that dilates blood vessels hints at new way to treat heart disease

April 19, 2018
Americans die of heart or cardiovascular disease at an alarming rate. In fact, heart attacks, strokes and related diseases will kill an estimated 610,000 Americans this year alone. Some medications help, but to better tackle ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Tausch
not rated yet Nov 23, 2012
What does not undergo 'pretrial' regardless of later function?
A cellular/organ/function checklist dry run?

Kudos. The process of elimination impressively applied:
"Unlike us, fetuses do not yawn contagiously, nor do they yawn because they are sleepy. Instead, the frequency of yawning in the womb may be linked to the maturing of the brain early in gestation."


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.