Semen analysis (part 2)

So now that you have dropped off your sample and have returned home to anxiously await the results. What will your semen analysis tell you?

The first stage of the analysis will look at the overall appearance of the ejaculate. The volume will be measured and it will be observed for its liquefaction and viscosity.

  • Volume – total volume can range from 1.5 – 5 ml. Although the volume does not play an important role in conceiving, if it is out of range it is likely there is cause for further investigation. A sample that contains too much volume is diluted and should be checked for possible infection. Low volume could be a result of collection issue, production issue or blockage. Possible conditions include: absence or blockage of the seminal vesicles, retrograde ejaculation, hormonal imbalance, or problems with the prostate. Sometimes there is an absence of the vas deferens. There is a natural decline of semen volume as we age, about 20% from ages 30 to 50.
  • Appearance – normal semen is opaque and greyish.
  • Viscosity – how thick or watery the sample is. Highly viscous semen may inhibit sperm motility and inhibit its ability to fertilize an egg.
  • Liquefaction – upon ejaculation, semen coagulates into a pearl like gel to help it adhere to the cervix. It should then liquefy within about 20 to 30 minutes and allow for the sperm to start swimming. Delayed liquefaction may indicate a problem with the prostate, the seminal vesicles, or the bulbourethral glands.
  • pH – the overall acidity of the sample. If it is too acidic there may be a blockage affecting the release of semen. A sample that is too basic is often consistent with an infection.

Ejaculate volume and concentration can change greatly. There are daily, weekly and seasonal variability in the results. This is one of the reasons why it is recommended to perform at least two and compare the results. It arises from three sources, the seminal vesicles, the prostate gland and the testes. It actually only becomes mixed together once ejaculation is complete. The opaque appearance of the ejaculate is a result of the large amount of protein that is contained within it and the slightly greyish turbid colour is the actual sperm. Only about 5% of the total ejaculate volume are the sperm cells. The rest of the volume comes from the fluids produced by the seminal vesicles, bulbourethral glands and the prostate gland. Visual inspection of the ejaculate can be helpful in determining if there is the presence of disease that could be affecting the release of sperm or affecting the accessory organs. Semen that lacks the turbid appearance usually means that the concentration of sperm is very low or non-existent. If there is a pink tinge to the ejaculate it signifies that there is fresh blood and likely damage to one of the glands or accessory organs. Brownish ejaculate is indicative of older blood and also requires further investigation to find the site of injury.

The second stage of the analysis will look more closely at the sperm in the sample. The sample is reviewed under a microscope. Using an overlaid grid pattern the sperm can be counted and their movement observed. At higher magnification, the shape is assessed.
Sperm analysis video (Advanced Fertility Centre of Chicago)

  • Sperm count / concentration – the concentration is the approximate amount of sperm in 1 mL of sample. To determine the total count, the concentration is multiplied by the sample volume. The WHO reference range is from 15 – 213 million cells per mL.
  • Motility – refers to the percentage of the sperm that move. Over 43% is considered favourable
  • Motility progressive – this is a percentage of the ability for the sperm to move in a forward direction. Ideally a sample would have a forward progression of at least 2 (1-4) or above 32%. Poor sperm motility may be caused by illness, a side effect of certain medications, dietary insufficiencies, or poor health habits (smoking).
  • Morphology – refers to the shape of the sperm cells. The head, mid-section and tail are evaluated, as well as the measurements and relative proportions of each. Normal forms should be above 4%. The production of abnormally shaped cells mostly occurs in the production and maturation stage within the testes. Abnormal sperm can have heads that are of abnormal size, more than one head or tail, or they can be missing important proteins essential for a particular aspect of the fertilization process. The evaluation utilizes the Kruger’s strict criteria.
  • Presence of white blood cells – white blood cells fight infection and are naturally occurring in the body as well as in semen. The total amount should be less than 1 million cells per milliliter. Higher than normal levels can be an indicator of infection present in the urogenital system.

Possible results and what they mean:

  • Asthenozoospermia – reduced motility. Major causes of reduced motility include: varicocele, poor diet, heat exposure, obesity, and toxin exposure.
  • Azoospermia – lack of sperm. Azoospermia can be either obstructive, meaning there is something blocking the release of sperm, or non-obstructive, which means that production of sperm is not taking place. Obstructive azoospermia is often due to varicocele, retrograde ejaculation, or other duct problems. The non-obstructive type is more consistent with hormonal issues, exposure to toxic substances, genetic or chronic health problems.
  • Oligospermia – lower than normal sperm count. As with azoospermia, this can be obstructive or non-obstructive.
  • Hypospermia (semen volume under 2mL) and Aspermia (no ejaculate produced). This is indicative of a complete or partial blockage, absence of seminal vesicles, a misdirection of semen (as is the case with retrograde ejaculation), or a hormonal imbalance. If a complete blockage is present but viable sperm cells exist, it is possible to have the sperm cells directly retrieved from the testes via a surgical procedure (TESE).
  • Teratospermia – abnormal sperm morphology. Something is interfering in the sperm maturation process that causes a malformation.

The semen analysis is not an exhaustive test for male fertility. There are many other factors that may contribute to the inability to conceive a child. One direction of testing is to examine the DNA within the sperm to see if it is genetically viable. The DNA Fragmentation Test is one such test that evaluates the integrity of the DNA to properly replicate and maintain integrity under stress.

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