In the past, almost all men with azoospermia underwent a diagnostic testicular biopsy to distinguish obstructive (blockage) from non-obstructive (sperm production) causes; normal sperm production found in the tissue suggests obstructive causes. Previously, most men with non-obstructive azoospermia had no options to father biologically related children. However, with the emergence of assisted reproductive techniques (ART) such as in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), a pregnancy could be initiated using very low numbers of sperm.
For men with non-obstructive azoospermia, we typically offer microsurgical-dissection testicular sperm extraction (microTESE), which gives the best chance of finding sperm within the testis that can be used with ART. In contrast, men with obstructive azoospermia can seek reconstruction to relieve the obstruction and attempt natural conception, or they can use surgically retrieved sperm with similar assisted reproductive techniques. To plan for the most appropriate treatment, it is highly valuable to be able to characterize the cause of azoospermia without a diagnostic biopsy.
Schoor RA, Elhanbly S, Niederberger CS, Ross LS. The Role of Testicular Biopsy in the Modern Management of Male Infertility. J Urol 2002; 167(1):197-200.
Journal of Urology.
In this study, Dr. Schoor and colleagues retrospectively reviewed the records of 153 azoospermic men. The authors recognized that classic texts of infertility described men with obstructive azoospermia having “normal” endocrine profiles, testicular volumes and long axis length, while men with nonobstructive azoospermia will have an abnormality in 1 or more of these parameters. However, the importance of these abnormalities had not been defined in the modern era of infertility.
They investigated a number of parameters including follicle stimulating hormone (FSH), leutenizing hormone (LH), prolactin, and testicular size, were analyzed as predictors for obstructive vs. non-obstructive azoospermia. FSH and testicular long axis were found to be the best individual diagnostic predictors:
- 96% of men with obstructive azoospermia had:
- FSH <7.6 mIU/mL
- Testicular Long Axis > 4.6cm
- 89% of men with nonobstructive azoospermia had:
- FSH >7.6 mIU/mL
- Testicular Long Axis < 4.6cm
Take Home: Not only did this study define clinical parameters to distinguish obstructive and nonobstructive azoospermia, but is also implies that testicular biopsy is generally unnecessary in the initial evaluation of azoospermia. Avoiding testicular biopsy reduced the cost and risk associated with evaluation of azoospermia for many men.
For the majority of patients with findings suggesting non-obstructive azoospermia, we now proceed directly to microTESE. Diagnostic biopsy is still performed for a small subset of patients whose findings suggest obstructive azoospermia, as a significant fraction of them may still have a sperm production problem within the testis. For more information, see: http://malefertility.jhu.edu/fertility_evaluation.php
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