Retrieving sperm surgically from the testicle is an effective treatment for infertility when it is combined with an assisted reproductive technology like in vitro fertilization (IVF) or intracytoplasmic sperm injection(ICSI). This is true both for men who are infertile due to a blockage of the tubes that carry sperm from the testes (obstructive azoospermia), and those who are infertile for other reasons (nonobstructive azoospermia).
Successful extraction rates
The success rate for retrieving sperm depends upon many factors, including the technique used and the underlying reason for infertility. While different sperm retrieval techniques give similar results, microdissection testicular sperm extraction (TESE) can be more efficient than regular TESE because less tissue is removed during the procedure and there is less scarring of the testes afterwards.
In men with nonobstructive azoospermia, success rates for TESE range from around 40 percent to 80 percent, depending upon which part of sperm development is affected. In men with obstructive azoospermia, success rates range from 68 percent to 75 percent.
Successful fertilization rates
Sperm retrieved through TESE are used in conjunction with a type of assisted reproduction technology, such as IVF. During in vitro fertilization, mature eggs are collected from a woman’s ovaries and fertilized by sperm in a dish in a laboratory. During ICSI, or intracytoplasmic sperm injection, a single sperm is injected directly into the egg. In both cases, the fertilized egg is then implanted into the woman’s uterus.
Success rates of these procedures are measured in two ways: whether the sperm fertilizes the egg and whether this results in pregnancy. These success rates depend not only upon the sperm that are retrieved during TESE, but also the techniques used to fertilize the egg and transfer the embryo to a woman’s body.
The fertilization rate for sperm retrieved during TESE and used with ICSI is around 59 percent, with successful pregnancies in around 48 percent of cases. Other methods of retrieving sperm give similar results as TESE.
When sperm retrieved by TESE are used with ICSI, the fertilization rates are lower for men with nonobstructive azoospermia than obstructive azoospermia. However, the pregnancy success rates are similar for those two.
In addition, the pregnancy rate is lower in vasectomized men, compared to those with other kinds of blockage of sperm. One study found that the pregnancy rate when men have sperm retrieved 10 or fewer years after vasectomy is 34 percent, but it drops to 8 percent for extraction 20 or more years after vasectomy. Another study found no decrease in success until 14 years after vasectomy. This may be due to poorer sperm quality the longer a man waits after the vasectomy.
Updated August 2014