4D Scan Shows Fetus Yawn in the Womb

Scientists have found that unborn babies not only hiccup, swallow and stretch in the womb, they yawn too

According to Reuters, 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.

The study was carried out on eight female and seven male fetuses 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.