Structural, mechanical, and material properties of fetal cranial bone.

The structural stiffness of 20 parietal bones from 10 fetal cadavers were tested under controlled laboratory settings. The slope at the onset of the load-deflection curve dictated the stiffness of the bone. These values were correlated with the bone's modulus of elasticity, mineral content, and bone density, as well as with anthropometric data. The stiffness exhibited as much as a Anthropometric factors correlated more with the change in stiffness than did material factors, such as changes in modulus, mineral content, and bone density. The bone exhibited a pronounced fiber orientation which significantly affected the modulus of the test specimens. The results are discussed in terms of obstetric management of preterm and term labor.