Azoospermia is the absence of sperm in the ejaculate. It is diagnosed and is usually confirmed by at least two semen analysis. Obstructive azoospermia is diagnosed when an obstruction, like a vasectomy, congenital conditions, or injury, prevents any sperm delivery during ejaculation. Obstructive azoospermia accounts for approximately 40 percent of all azoospermia cases.
Causes of Obstructive Azoospermia
Problems with the ductal system or issues with ejaculation can cause obstructive azoospermia. These include:
- when the ducts are ligated (tied), as in a vasectomy
- blockages due to trauma or infection
- if the ducts are absent due to congenital conditions such as CABVD (congenital absence of the vas deferens), which is associated with cystic fibrosis mutations
- by dysfunction in the process of ejaculation, which may be caused by neurological damage from surgery, diabetes, or spinal cord injury.
Treatments for Obstructive Azoospermia
Men who have obstructive azoospermia may need surgery to correct the obstruction, which may make natural pregnancy possible without assisted reproductive technology. A vasectomy reversal may offer couples an option to conceive naturally. The time since the man’s vasectomy, the woman’s age and other confounding variables can impact overall success rates. The American Society for Reproductive Medicine (ASRM) estimates that 20 to 40 percent of couples in which the man gets a vasectomy reversal can get pregnant without assisted reproductive techniques.
Pregnancy and Obstructive Azoospermia
If surgery is able to correct the obstruction causing azoospermia, couples may be able to conceive naturally without the help of fertility treatments.
However, there are sperm retrieval techniques that can also allow for conception. Men with obstructive azoospermia may be able to father a child through retrieval of sperm directly through the testis or epididymis, followed by IVF with intracytoplasmic sperm injection (ICSI). Common methods of sperm retrieval include microsurgical epididymal sperm aspiration (MESA), percutaneous epididymal sperm aspiration (PESA), testicular sperm extraction (TESE), and percutaneous testicular sperm extraction (TESA).
During IVF, sperm retrieval can be performed on the same day as the egg retrieval, or it can be done some time before. Many fertility clinics prefer to use fresh sperm. Repeated sperm retrievals can be performed, though there is a recommended wait of 3 to 6 months between retrieval procedures.
In most cases, ICSI—the process by which an embryologist physically injects a single sperm into an egg to promote fertilization—will be used to fertilize the eggs as retrieved testicular sperm does not have the number of motile sperm necessary to permit IUI or IVF without ICSI.
Dr. Natan Bar-Chama, Director of the Center of Male Reproductive Health at RMA of New York, is a board certiﬁed Urologist and Male Infertility Specialist. Following his urology residency at the Albert Einstein College of Medicine, he was awarded the New York Academy of Medicine F.C. Valentine Fellowship and sub-specialized in Male Reproductive Medicine and Surgery at The Baylor College of Medicine in Houston, Texas. For the last 20 years, Dr. Bar-Chama has been the Director of Male Reproductive Medicine and Surgery and is on faculty in both the Departments of Urology and Obstetrics/Gynecology and Reproductive Science at The Icahn School of Medicine at Mount Sinai.