Prenatal growth of human ulna and estimation of CRL and CHL based on osteometry on fetal ulna.

Abstract

In dealing with fetal bone growth and fetal age estimation from osteometry,
the earlier osteometric studies were done from chemically preserved fetuses,
photographs, radiographs and ultrasonographs which would not give perfect
results. In the present study osteometry was taken directly on naturally
prepared fetal ulna bones for the first time. There were six new osteometric
measurements on human fetal ulna introduced. Possible osteometric
measurements were taken on 912 fetal ulna bones (right and left) from 456
fetuses having age range between 11 weeks to 40 weeks of intrauterine life.
Bilateral and bisexual differences were analyzed. It is found that there is
positive growth trend found in fetal ulna on the basis all the osteometric
measurements taken on fetal ulna. The fastest rate of growth in the length of
fetal ulna was observed in females during 11 weeks to 16 weeks of the
intrauterine life of human fetus. For every 1 mm in the CRL (crown- rump
length), the Maximum Length of Ulna is increased by .306 mm. As there is
no established scale available for fetal age estimation from fetal bones, even
anatomists found difficulties to provide precise opinion regarding the age of
human fetus from fetal bones in suspected murder cases. In the present study
regression values were calculated and found out a formula to estimate CRL and CHL (crown-heel length) from the osteometric measurements on fetal ulna. The age estimation is a crucial factor in dealing with medico-legal
cases.