Morphology of the corpus callosum in human fetuses.

Shape and size of the human fetal corpus callosum of a relatively racially homogeneous southern Indian sample population were studied in midsagittal sections of formalin fixed brains. Length of corpus callosum and width of its genu, body, and splenium were measured and the data statistically analyzed. Presence of an isthmus between the body and splenium did not correlate with the measured variables. There was no significant gender difference. The variables correlated significantly among each other but only callosal length and genu width correlated with gestation age. Significant absolute increase occurred in callosal length and genu width, whereas body and splenium widths remained the same. Simple regression equations to estimate the callosal length and genu width for a given age are derived.