"Soft cartilage" refers to a type of flexible tissue found in our bodies. It is not as hard as bones, but still provides support and structure to different parts, like our joints and the tip of our nose. Full definition
Still, your doctor may tell you that your baby's skeleton structure, which consisted of fragile and soft cartilage before, starts turning into hard bone tissue. (bebezclub.com)
Before that happens, bone growth takes place between the two pieces, where soft cartilage generates new cells. (sciencemag.org)
His or her skeleton is gradually beginning to harden, transforming from soft cartilage to harder bone, although the bones will continue to remain somewhat flexible so your little one can fit more easily through the birth canal during delivery. (pregnancy-baby.com)