Crown-Rump Length estimation of Human Fetuses by external surface area of Right Parietal bone

Background: Despite enormous volume of research devoted to the skeletogenous and to the quantitative studies of the developing and mature skeleton, the growth of skull in respect to its surface area is still never been comprehensively studied. Since classical study of Streeter reported gestational age estimation from crown-rump length (CRL), numerous investigators have studied and reported various measures of fetal growth during pregnancy such as biparietal diameter, diaphyseal length of long bones and even cephalometric growth analysis. Present study was done in dried fetal skull bones by calculation of their external surface area and estimation of linear correlation with crown-rump length and hence determination of gestational age. Aim: To establish the correlation between the external surface area of right parietal bone and crown-rump length, to predict fetal age from crown-rump length and calculation of growth rate of right parietal bone. Material and methods: Fifty apparently normal fetuses ranging from 12 cm ? 42 cm CR length of both sexes were obtained from the Department of Obstetrics and Gynecology, of our native hospital. After measuring crown-rump length of each fetal skull after removing brain tissue via foramen magnum was then kept for maceration in running tap water. After complete maceration and separation of right parietal skull bone, measurement of external surface area of right parietal skull bone was obtained using wet cotton cloth, marker pen and graph paper. Results: The regression values were plotted in the graph and these values were found to cluster around the standard straight line and are in hand with the straight line indicating highly significant results. Conclusion: In the present study, CR length was estimated from external surface area of right parietal bone. A definite correlation was observed between external surface area of right parietal bone and CR length.