Little*princess, I have heard a few times that babies are not born with knee caps... But I don't think it's true.

I found this
Kneecaps form about the fourth month of fetal life. However, they don’t show up on x-ray very well because they’re not ossified, or bony. At this point in life, the kneecaps are made of a cartilaginous material. The growth centers surrounding the kneecap form late in developmental life in utero and may not appear until just before or just after the infant is born.
Thought you might be interested to know

Tanya