This was just too cool!
While ultrasounds can be a useful diagnostic tool, I don’t agree with their routine use, and especially not with their non-medical use (such as businesses that sell “keepsake ultrasounds” with names like “Womb with a View”), this is just too neat to pass up.
Using 4-D ultrasounds, some researchers have caught babies as young as 12 weeks of gestation yawning. In trying to figure out why creatures yawn (including animals, adults, and now fetuses), they’ve ruled out lack of oxygen or too much carbon dioxide as the reason for a yawn. It appears to happen after the fetuses have awakened out of sleep, so is in some way connected to the sleep-wake cycle. I didn’t read the full article — only skimmed much of it — and it seems that there were some errors in translation (I noted at least a couple of fragmentary sentences, or absent words). The links are all in French, and the abstract is written in both French and English, but the article itself is all in English.
Anyway, the topic is just fascinating, and shows how little we actually know about fetal development, even though our knowledge base is far and away better than what it was just a decade or two ago.