Bouncing baby boy.

Somebody just gave birth to a bouncing baby boy. Sounds awful in my literal mind.
I have two daughters, both grown now, and have seen probably thousands of babies, and not a one ever bounced in my presence. And I’ve never thought “bounce” upon seeing a baby. There is a birthing method where such a thing would be possible, I guess, but I’m sure anti-bounce measures are in place.
Okay, cut to the chase. Where did the phrase come from? And do baby girls bounce too?
Peace,
mangeorge

The Maven’s Word of the Day

Aside the alliteration, it’s not used with girls because they historically aren’t expected to exhibit or be rewarded for noise and activity.