Obstructive azoospermia

Obstructive azoospermia (AO) is less serious than the secretory type and does not produce as many problems to conceive.

The absence of spermatozoa in the ejaculate is due to problems in the efferent ducts or epididymis, however, the testicles are able to produce sperm. In order to find sperm, it is necessary to retrieve them from the obstructed duct by aspiration.

Patients with obstructive azoospermia have normal hormone levels and regular testis size. To make sure a patient has such fertility alteration, seminograms have to be performed. Moreover, the study is followed up by a testicular biopsy, carried out to determine whether the testicles are able to produce sperm. Later on, the exact location of the obstruction must be identified. Sperm will be removed for its use in subsequent assisted reproduction treatments.

Most common causes

The obstruction of the sperm transportation ducts is caused by several factors:

  • Vasectomy: ducts are obstructed as a contraceptive measure.
  • Complications after surgical intervention: a seminiferous duct has been cut off.
  • Congenital or genetical alterations: they may hinder the proper development of the ducts (bilateral cryptochirdism).
  • Diseases: mumps or meningitis suffered by children before puberty may block sperm ducts.
  • Inflammations, cysts or traumas: either in the epididymus, the prostate, the urethra, or the ejaculatory or efferent ducts.