Black Section Separator
Important Developments in the Hardening of Babies' Bones in the Womb
Bones begin to develop in the womb during the first several weeks of pregnancy
Primary ossification centers occur in the long bones during the 12th week of pregnancy
The spongy cartilage skeleton progressively changes into solid bone as the pregnancy proceeds.
Hardening and Mineralization
The bones begin to stiffen and mineralize around the end of the second trimester (abou
t 20 weeks)
The motions and interactions of the fetus with the environment contribute to bone strength
Throughout childhood, the bones continue to develop, strengthen, and remodel
The process of bone formation and growth lasts into puberty.