SHAFAQNA (Shia International News Association) – Researchers are using footage of foetuses at different stages of growth to show that healthy babies yawned less as they approached their birth dates. Scientists at Durham and Lancaster Universities said that while it remained unclear why unborn babies yawned, the movement may be related to the maturation of their central nervous systems. "It may be that, in order to get part of the brain to mature in the correct way, you need a certain stimulus, and yawning might be that stimulus," said Nadja Reissland, a psychologist who specialises in foetal development.
Reissland and others used 4D ultrasound scans to capture a rapid sequence of images for eight female and seven male foetuses at 24, 28, 32 and 36 weeks. All the unborn babies were healthy and were scanned for 20 minutes. The researchers went through the images frame by frame and counted the yawns and other movements made by the babies. Over 58 scans, the team recorded 56 yawns and 27 other mouth movements. Yawns can be distinguished from other movements because a yawning mouth opens more slowly than it closes. Similar yawning rates were noticed in boys and girls.
One noticeable factor was that yawning decreased steadily from nearly twice every 10 minutes in foetuses at 24 weeks, to none at 36 weeks. "Unlike us, foetuses 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 foetuses 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." Reissland said.
Source: The Guardian