Thanks to new technologies for four-dimensional studies, several researchers from the British Universities of Durhan and Lancaster have discovered that fetuses, inside their mother, also yawn. But how have they managed to distinguish a normal mouth opening from a yawn? Why do they do it?
The finding has been possible thanks to the study of 15 healthy fetuses during the final weeks of gestation (between 24 and 36) with 4D technology. In this period of development, babies already have the essential structures to perform movements in the womb, including the opening of the mouth. To distinguish between a simple mouth opening and a proper yawn, the scientists interpreted that, if it is too long an opening, then it is a yawn. In the words of Dr. Reissland, from the University of Durham, ” to be able to differentiate them we based on the duration of the mouth opening using 4D ultrasound video sequences that allowed us to see closely all the mouth movements made by the fetus”.
This study has not only revealed that fetuses also yawn but has also revealed the number of times they perform this act (six yawns per hour) and when they occur most frequently (they decrease from week 28 of gestation Furthermore, since seven male and eight female fetuses were studied, it has been found that sex does not influence this parameter.
Why do fetuses yawn?
In human beings, yawning is contagious, even this fact is more notable among relatives . However, during pregnancy it is impossible for yawning to “stick”. As the researcher points out, “contrary to what happens to us, fetuses cannot yawn because of contagion or because they are sleepy. The frequency of yawning in the womb may be related to the maturation of the brain early in gestation, for which can be a good measure to check the health of the fetus “. In fact, yawning could be linked to the development of the central nervous system itself , although researchers have been inconclusive in this regard, since, as Reissland herself indicates, “they are hypotheses that should be investigated from now on” .
Until now it was known that babies, inside the womb, could move, hiccup, panic, and so on. Now, the confirmation of yawning and its possible link to brain development open the doors of new diagnoses and control of the baby in early times. The study has been published in the specialized journal PlosOne.
