I'd call a newborn baby an adult fetus...haha.
You could only call the baby a virgin if it didn't have a twin brother.
Who knows what preborn babies do in there? Nine months is a lot of time!
Myself, I think I was always trying to peek outside. har har.
I like kangaroo babies.
Their fetal baby is called a "Joey".
Weighing less than two grams, it climbs into its mothers pouch after she licks a path for it to follow.
Her milk will change during its development..
And whats really odd about the Joey
Is has an semi developed backup (a twin in suspense).  It hangs out in the womb for a few weeks after Joey's birth.
If conditions are good, the twin will crawl out.
I think thats incredible how these macropods live.
They live in mobs, ya know.