Current Weather
The Spy FM

When Fetuses Yawn In The Womb

Filed by KOSU News in Science.
November 21, 2012

Why people yawn is a mystery. But yawning starts in the womb.

Past studies have used ultrasound images to show fetuses yawning, but some scientists have argued that real yawns were getting confused with fetuses simply opening their mouths.

So Nadja Reissland, a researcher at the University of Durham in the United Kingdom, used a more detailed ultrasound technique to get images of fetal faces that could distinguish a true yawn from just an open mouth.

“They seem to open their mouths widely much less often than they yawn,” Reissland says.

What’s more, she found that yawning was common at 24 weeks but then dropped to zero at 36 weeks, according to a report by Reissland and her colleagues in the journal PLOS ONE.

Reissland believes that fetal yawning may somehow help trigger brain maturation, by acting as a kind of self-stimulation for the developing fetus.

“It could be that yawning is something which you need in order to have a functioning brain, which is a hypothesis,” she says, adding that she would like to compare yawning in healthy fetuses, like the ones she studied, with yawning in fetuses that have medical conditions.

Reissland says she suspects that yawning has a different function for adults than for fetuses. Most studies on yawning have focused on its contagious nature. But some research suggests that children are immune from “catching” another person’s yawn until about five years of age.

And Reissland says one study showed that babies don’t imitate their mother’s yawns, even though babies do imitate mouth movements such as smiles and pursed lips. “How is it possible that these babies can imitate mouth movements, but they don’t imitate the yawning?” Reissland wonders. [Copyright 2012 National Public Radio]

Leave a Reply

10AM to 11PM On Point

On Point

On Point unites distinct and provocative voices with passionate discussion as it confronts the stories that are at the center of what is important in the world today. Leaving no perspective unchallenged, On Point digs past the surface and into the core of a subject, exposing each of its real world implications.

Listen Live Now!

11AM to 12PM The Story

The Story

The Story with Dick Gordon brings the news home through first-person accounts. The live weekday program is passionate, personal, immediate and relevant to listeners, focusing on the news where it changes our lives, causes us to stop and rethink, inspires us.

View the program guide!

12PM to 1PM Fresh Air

Fresh Air

This one-hour program features Terry Gross' in-depth interviews with prominent cultural and entertainment figures, as well as distinguished experts on current affairs and news.

View the program guide!

Upcoming Events in your area (Submit your event today!)

Streaming audio and podcasts

Stream KOSU on your smartphone

Phone Streaming

SmartPhone listening options on this page are intended for many iPhones, Blackberries, etc. with low-cost software applications available to listen to our full-time web streams, both News on KOSU-1 and Classical on KOSU-2.

Learn more about our complete range of streaming services

We're perfecting the patient experience - Stillwater Medical Center