Normal and abnormal development of the epididymis of the fetus and infant.

The fetal epididymis shows a weak periodic acid Schiff (PAS)-positive secretion by the 25th week of gestation which gradually increases during the following weeks and reaches its peak in the later weeks of pregnancy. It decreases again after the 3rd month of life. The organ continues to secrete throughout childhood, although in a much reduced degree. It can be assumed that androgens, produced by the fetus in response to stimulation by maternal and placental hormones, are responsible for the secretion of the organ during fetal life. The normal development and function of the epididymis in the fetus and infant can be impaired in the presence of various congenital malformations. Hormonal therapy to the mother during pregnancy may also affect the organ. However, it is possible that in the absence of any serious structural damage to the organ, the purely functional changes may only be of a temporary nature and not detrimental to fertility in later life.