Azoospermia refers to a condition in which no sperm are found in the ejaculate. Azoospermia is different than anejaculation, which is when the man cannot ejaculate.
Azoospermia with a Low Ejaculate Volume
Azoospermia with a low ejaculate volume (typically less than one milliliter) may be caused by three factors:
Obstruction of the ejaculatory ducts
This issue results in the ducts emptying semen into the urethra. This may be treated by using surgery to open the ejaculatory ducts, or if surgery is not possible or unsuccessful, to extract sperm directly from the testis or epididymis for in vitro fertilization (IVF).
Retrograde ejaculation of sperm into the bladder
Rather than being propelled forward during ejaculation, sperm goes backwards into the bladder. This may be treated by medicines to strengthen the bladder neck, or retrieving sperm from the bladder for artificial insemination or IVF.
Conditions such as CBAVD (Congenital Bilateral Absence of Vas Deferens)
These conditions cause problems in development of the prostate and seminal vesicles. These may be treated by extracting sperm directly from the testis or epididymis for use by the female partner during IVF.
Azoospermia with a normal semen volume
Azoospermia with a normal semen volume may be caused by obstruction of the epididymis or vas deferens (“obstructive azoospermia” or OA) or to problems with spermatogenesis (“non-obstructive azoospermia” or NOA). A doctor can distinguish between obstructive and non-obstructive azoospermia with about 90% accuracy by measuring testis size and FSH. Biopsy of the testis is occasionally necessary to determine whether azoospermia is obstructive or non-obstructive.
A man may be born with obstructive azoospermia or he may have had a vasectomy, injury or infection as a cause later in life. The treatment of obstructive azoospermia is to correct the obstruction with microsurgery, if possible. If surgical reconstruction is not possible or successful, sperm is extracted from the testis or epididymis. As it is immature, sperm extracted from the testis or epididymis must be used in IVF, typically with intracytoplasmic sperm injection (ICSI).
As with obstructive azoospermia, non-obstructive azoospermia may be present from childhood or acquired later in life due to injury or infection. A man with non-obstructive azoospermia may be treated with medicine to stimulate spermatogenesis, requiring three or more months of treatment. If sperm is not found in the ejaculate after treatment or if the couple prefers immediate treatment, sperm is extracted from the testis for IVF.
Sperm Extraction for Azoospermia
A surgeon may use many different ways of extracting sperm from the testis, including open surgery, microsurgery, using a needle to draw out sperm, and retrieving sperm from the testis or epididymis. All choices are possible with obstructive azoospermia, as large numbers of sperm are present in the testis. However, non-obstructive azoospermia limits a surgeon’s choices. In order to obtain enough sperm, a surgeon may use microsurgery, open surgery, or multiple needle punctures from the testis.
Extracted sperm may be frozen for later use with IVF. Advantages of freezing sperm include that the couple may choose a date for the extraction procedure, the female partner may be present for the extraction, and the couple will know whether sperm was able to be extracted before IVF is done. There’s no difference in the success of IVF with frozen sperm or sperm extracted on the day of IVF.