Although not a comprehensive measure of fertility, the semen analysis, if abnormal, may suggest that the probability of achieving fertility is statistically low. Among the numbers on the test, the sperm concentration and motility appear to correlate best with fertility. Two well-performed semen analyses can often suggest a diagnosis or direction. Normal values for semen analysis:
The evaluation of the various shapes of sperm is termed morphology. Several descriptive systems exist to evaluate morphology, and within each classification system, sperm are designated normal or abnormal based on a list of criteria. It is believed that sperm morphology may correlate with a man’s fertility potential, but in actuality, it has only been shown in studies to correlate with the ability of sperm to penetrate and fertilize eggs in the setting of in vitro fertilization (IVF).
It is not been convincingly demonstrated that sperm morphology correlates with the ability of couples to conceive with either sexual intercourse or intrauterine insemination (IUI). Sperm morphology may also be a sensitive indicator of testicular health because sperm morphology is largely determined during sperm production in the testis. The main role of morphology in the male evaluation is to complement the semen analysis data and better estimate the chances of fertility.
Key Points for Patients
- Recognize that not all semen analysis labs are equivalent. Some labs, especially those associated with fertility centers, may be more used to doing a semen analysis and have better quality assessment and reports.
- Semen quality varies with collection technique, so follow the instructions as best as you can.
- Abstain from ejaculation for 2-4 days prior to collection. Longer or shorter abstinence than this may result in artificially high or low concentration or motility.
- Clean or sterile containers should be used for collection. The entire specimen must be collected. Regular condoms and lubricants should be avoided as they may kill sperm.
- If collecting the sample at home, keep it at body temperature during transport (shirt pocket); it should be delivered within 1 hour of collection.
Semen Leukocyte Analysis On a routine semen analysis, “round” cells are often found in addition to sperm with tails. These “round” cells are either immature sperm forms (spermatocytes) or white blood cells (leukocytes). It is important to distinguish between these two cell types because the treatments differ.
Karyotyping Also infrequently indicated, chromosomal analysis is performed in men with low (less than 5 million) or no sperm in the ejaculate.