How does a Sperm DNA test help decide the best Fertility treatment for me?
When facing the problem of male infertility and deciding on which treatment would be best, it is relevant to note that the Semen Analysis
test is the first step for evaluating male fertility potential. However, it is a basic test and the parameters assessed are limited as it cannot provide details on the following – DNA quality of the sperm, other functional aspects of sperm, prediction of male infertility or likely success of ART (Assisted Reproductive Technology).
Damage to the DNA, such as fragmentation and denaturation, can be analysed as they can have adverse effects on fertilization and embryo development, as infertile men have poorer sperm DNA integrity and a larger proportion of sperm DNA damage than fertile men.
There are various methods available to test for sperm DNA integrity and these are briefly explained below:
SCSA (Sperm Chromatin Structure Assay), Comet, SCD or Halo (Sperm Chromatin Dispersion) and TUNEL (Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labeling).
While the Comet test detects single and double-strand DNA fragments in individual sperm, the TUNEL test directly measures sperm DNA and is usually used for infertile males who are idiopathic, have severe oxidative stress-related abnormal semen quality and contribute to the couples considering ART to overcome their infertility problem. The SCD or Halo test is an initial chemical denaturation of sperm cells, which indirectly measures the damaged area through protein denaturation in an acidic solution.
However, what is known as the Gold Standard in DNA integrity is the SCSA (Sperm Chromatin Structure Assay). The results of this advanced test help both the patient and the doctor in making a clinical diagnosis and assist in managing and treating male infertility. The SCSA test is a rapid, non-biased flow cytometer machine measurement and the main factors of this test are to assess the percentage of DFI (DNA fragmentation index) and HDS (High DNA Stainability). The DFI results show the percentage of sperm that have DNA fragmentation and the HDS results show the percentage of sperm with abnormal nuclear proteins and chromatin structure that may inhibit fertilization or result in an unsuccessful pregnancy.
The advantages of this test are quick analysis of a large number of sperm cells and a large sample. Also there is a high rate of reproducibility (extent to which consistent results are obtained when an experiment is repeated) and freezing of the sperm does not affect the test, making it more convenient.
Since its invention in 1980, the SCSA test has been performed on thousands of human and animal sperm samples and it is based on well established research and methods. It provides robust statistical data with exceptional precision and repeatability. It is a standardized test, performed according to strict protocol. The clinical report is based on 2 independent measurements of every single sample, which ensures a trustworthy clinical report with high prognostic value. It has been found to have the most relevant clinical threshold values in relation to fertility and has shown to be an independent predictor of successful pregnancy both in couples undergoing IUI (intrauterine insemination) and in first pregnancy planners. It also has the potential to contribute to more successful ART treatments.
Among the many causes for sperm DNA fragmentation, the test results can be used to link possible factors responsible, such as oxidative stress, infection, Leukocytospermia, recent episode of high fever, elevated testicular temperature, Varicocele, advanced male age, obesity, drugs, chemotherapy and radiation therapy, cigarette smoking and environmental toxins, alcohol, occupational exposure such as dyes, pesticides, chemicals and fertilizers. In cases where the cause of the high DNA fragmentation levels can be identified, further clinical treatment can be recommended accordingly. In the case of previous failed fertility treatments or cases where there is no apparent cause of infertility with both partners, a sperm DNA test can reveal vital information about the sperm DNA integrity, thereby answering previously unanswered questions or helping the patient and clinician decide on the best clinical management option. Studies have shown a link between recurrent pregnancy loss or miscarriages and sperm DNA integrity, so couples with a history of recurrent pregnancy loss would also benefit from a Sperm DNA fragmentation test.
While a sperm DNA fragmentation test is not recommended as a routine investigation, all the information provided above, definitely substantiates that there are certain instances when a Sperm DNA fragmentation test will most definitely reveal more information and help in further treatment options for the patient and clinician. Remember to always check the lab where your Sperm DNA test is being done to ensure a clinically reliable report!