Azoospermia, is relatively uncommon, occurring in about 1% of all men and in 10-15% of infertile men. It can be caused by various factors, including hormonal issues, genetic conditions, obstruction of the reproductive tract, or testicular failure. The specific prevalence can vary based on the population studied and the underlying causes considered.

Obstructive azoospermia is when the testicles are able to produce sperm but there is an issue that prevents the sperm from travelling from the testis and coming out. 

What can cause Obstructive Azoospermia?

• The most common example is a vasectomy 

• Cystic Fibrosis (congenital lung disease) - in nearly all men with Cystic Fibrosis - the vas and epididymis ducts do not form properly. A large proportion of men (>95%) with Cystic Fibrosis do not have any vas deferens (congenital bilateral absence of the vas deferens).

• Most men with Cystic Fibrosis do produce sperm normally and therefore, sperm extraction is required to have a baby.

• Ejaculatory Duct Obstruction - this can be either blocked by congenital cysts (some men are born with) or from infections.

• Phimosis - Narrowing of the foreskin which prevents semen to come out properly. 

• Scarring along the ducts - sexually transmitted infections can cause blockage along the ducts that sperm swim.

NOA is a set of disorders that cause a male to not produce sperm in the ejaculate. All these conditions either lead to a decrease in production or no production of sperm at all. 

What can cause Non-Obstructive Azoospermia?

There are 2 main categories of causes of NOA. 

Pre-Testicular - these are caused by conditions that disrupt the hormones from producing sperm appropriately. 

• Hypogonadotropic Hypogonadism - pituitary gland is not functioning properly to make the necessary hormones that allow for sperm production.

• Hypothyroidism 

• Medications 

• Kallman’s Syndrome 

Testicular - there is an underlying issue within the testicle preventing the normal production of sperm.  

• Varicoceles - in rare cases can cause azoospermia by hindering normal sperm development.

• Bilateral undescended testicles 

• Testicular Cancer 

• Previous radiation or chemotherapy

• Mump orchitis 

• Genetic syndromes such as Klinefelters (XXY) 

OBSTRUCTIVE AZOOSPERMIA TREATMENTS

• Microsurgical Vasectomy Reversal

• Microsurgical Reconstruction  

• Sperm extraction (sperm retrieved can be used for in-vitro fertilization) 

• Transurethral Resection of the Ejaculatory Duct - surgical procedure where the blockage is removed in the urethra.

• Circumcision 

   

NON-OBSTRUCTIVE AZOOSPERMIA (NOA) TREATMENTS

• Depending on the underlying etiology, this may involve medications or surgical sperm extraction (mTESE)

• If testosterone is found to be low, medications will be used to boost your own testosterone to produce more sperm.

• Microsurgical Testicular Sperm Extraction (mTESE) - during this procedure, doctors are able to find sperm in ~50-65% of cases.