First-Line Examination: The Essential Spermogram
Semen Analysis: A Key Step in Male Fertility Assessment
Second-Line Examination: Investigating Sperm Abnormalities
When semen analysis reveals abnormalities in sperm concentration, motility, or morphology, further diagnostic tests are necessary to determine the underlying cause and guide treatment. These additional examinations provide deeper insights into the prognosis and help tailor the most appropriate therapeutic approach.
SCROTAL ULTRASOUND
A scrotal ultrasound is a quick, painless imaging test used to assess male reproductive health. Performed by a radiologist, it helps evaluate the position, size, and condition of the testicles, as well as the epididymis, which plays a key role in sperm maturation. This exam is essential for detecting any abnormalities, such as inflammation, blockages, or other issues that could affect fertility. Additionally, a Doppler ultrasound may be used to check for varicocele—a common condition where the veins in the scrotum become enlarged, potentially impacting sperm quality. This simple test provides valuable insights for diagnosing and addressing male fertility concerns.
HORMONE TESTING
In some cases, hormone testing may be recommended, particularly when sperm abnormalities are detected—especially if the patient also experiences issues with libido or erectile function.
The initial assessment typically includes measuring FSH (Follicle-Stimulating Hormone) and testosterone levels. If these results indicate any abnormalities, additional tests will be conducted to further evaluate the underlying causes.
KARYOTYPE ANALYSIS
A karyotype is a chromosomal analysis performed on a blood sample in a specialized laboratory. In men, the normal chromosomal composition is 46,XY. However, certain chromosomal abnormalities can impact sperm quality.
For instance, Klinefelter’s syndrome occurs when an extra X chromosome is present, resulting in a 47,XXY karyotype, which can affect sperm production. Structural anomalies, such as translocations or inversions, may also be detected.
Approximately 7% of infertile men have chromosomal abnormalities. This test is typically recommended when sperm concentration falls below 10 million/ml or in cases of non-obstructive azoospermia, which accounts for 10–15% of male infertility cases.
Other Genetic Tests
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Y Chromosome Microdeletion Testing
The Y chromosome contains a critical region on its long arm known as the AZF (Azoospermia Factor) locus, which is divided into three subregions: AZFa, AZFb, and AZFc. Microdeletions in these areas—where small portions of genetic material are missing—can lead to significant abnormalities in spermatogenesis (sperm production).
AZFc microdeletions are the most common and are associated with severe oligospermia (low sperm count) or azoospermia (absence of sperm).
AZFb microdeletions cause azoospermia due to a blockage in spermatogenesis.
AZFa microdeletions lead to azoospermia with a complete absence of sperm-producing stem cells, a condition known as Sertoli cell-only syndrome.
AZF microdeletions are considered de novo genetic anomalies, meaning they occur spontaneously and are not inherited. However, if a father carries a Y chromosome microdeletion and conceives a son through medically assisted reproduction (MAR), the child will also inherit this genetic anomaly.
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CFTR Gene Mutation Testing
Mutations in the CFTR gene (cystic fibrosis gene) are systematically screened in men with congenital bilateral absence of the vas deferens (CBAVD), a condition responsible for obstructive azoospermia.
If a CFTR mutation is detected, the patient’s partner should also be tested for this genetic anomaly. Genetic counseling is strongly recommended to evaluate the risk of cystic fibrosis in potential offspring.