Pre- and post-natal growth of the human ductus epididymidis. A morphometric study.

A histometric study of the development of the human epididymis from the fetal period to adulthood has been carried out in males without testicular or related pathology, distributed into the following groups: (I) fetuses (between the 28th and 37th week of pregnancy); (II) newborns (1-30 days of age); (III) infants (2-4 months of age); (IV) infants (5-12 months of age); (V) infants (1-4 years of age); (VI) children (5-14 years [prepubertal]); and (VII) adults (15-60 years of age). For each age group and each epididymal portion (efferent ducts, caput, corpus and cauda epididymidis) the parameters measured were (1) total surface (epithelium + muscular layer + lumen); (2) the surface occupied by the lumen; (3) the surface occupied by the muscular layer; (4) total diameter of the duct; (5) total diameter of the lumen; and (6) the height of the epithelium. The results of the present study revealed that the development of the efferent ducts and ductus epididymidis follows a biphasic pattern. A progressive development occurs from the fetal period to infants 2-4-months of age. However, this development is transient and regresses during infancy (groups IV and V). At childhood (group VI), a definitive development is initiated and completed at puberty (group VII). These changes seem to be related to the androgen-dependence of the epididymis, the different stages of testicular maturation, and the steroidogenic activity of Leydig cells.