male fertility testing

Computer Assisted Semen Analysis (CASA) is a sophisticated technology involving the use of computer-based technology to analyze semen samples. Here are some key aspects of CASA:

• ‍Objective Analysis: CASA provides a more objective and standardized assessment of semen quality compared to traditional manual methods. It reduces human error and variability in interpreting results.
• ‍Parameters Measured: CASA systems can analyze a wide range of sperm parameters, including concentration (sperm count), motility (movement), velocity (speed), and morphology (shape and structure of sperm).
• High Accuracy: The use of advanced imaging and software allows for precise measurements of sperm characteristics, providing detailed insights into sperm health.
• ‍Consistency: CASA systems ensure consistent results, which is crucial for monitoring changes in sperm quality over time or evaluating the effectiveness of treatments for male infertility.
• ‍Rapid Analysis: The technology allows for quicker analysis of samples compared to manual methods, enabling faster turnaround times for results.

An appointment will be scheduled for you to collect a semen specimen in one of our offices. IVF1 has a quiet comfortable private room to collect the semen specimen. The ejaculate is collected into a cup which you will give to a staff member. After that you can leave! We will process the specimen and then complete the analysis.

Absolutely. We know this can be a difficult process, and your partner is welcome to help you out if you like.

The determination of the number of sperm that are moving rapidly in a forward progressive manner is of paramount importance in the evaluation of male fertility. In an average semen analysis, there will be some sperm with no movement, some that are moving slowly and/or some that do not move in a forward direction. These sperm are less likely to be able to produce a pregnancy easily.

With computerized semen analysis, the computer identifies and tracks every sperm seen in under the microscopic field. Over a fraction of a second, the path the sperm has traveled is analyzed and many different parameters can then be computed with a high degree of accuracy.

In the picture below, the squiggly green lines are the paths of individual sperm. The red dots mark sperm that are not moving.

Some of the parameters that are calculated include:

• Overall motility: Percent of sperm showing any movement
• Rapid motility: Percent of sperm traveling at a speed of 25 um/sec or faster
• Linearity: Percent of sperm moving in a straight line path
• Progressive motility: Percent of sperm moving rapidly AND in a straight path
• Mean velocities: An average speed for all sperm in the field of view
• Amplitude of lateral head displacement: The average distance that the sperm head “wiggles” back and forth while moving

A computerized semen analysis will give many more parameters that are useful to the fertility specialist. Learn about the measurements of sperm motility.

Here is what a sample report looks like:

Medical studies have evaluated these parameters individually and have found that many are independent predictors for male fertility. In other words, it is now possible to identify men with fertility problems even though their standard semen analysis may seem completely normal.

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The appearance of sperm under a microscope is used to evaluate a man’s fertility. In any given semen specimen, some sperm will have a normal appearance and some will have an abnormal appearance. Normal fertility is determined by what percentage of the sperm have a normal appearance.

Criteria for sperm morphology

In the past, different criteria have been used to distinguish normal from abnormal sperm, and different “utoff levels have been used for what is considered normal fertility. For many years, infertility specialists used criteria that were established by the World Health Organization (WHO). However, several recent studies found that the WHO criteria was not very good at distinguishing between fertility and infertility.

Strict Morphology

For this reason, many of us have now switched to a different criteria known as strict morphology. It has also been referred to by the name of the doctor who developed it, Thinus Kruger, and is often called the Kruger morphology. The concept behind strict morphology, as the name suggests, is to evaluate sperm much more closely than we had in the past and have a stricter determination for what is considered normal.

For example, older criteria would consider fertility normal with 30-50% normal sperm in a sample. A normal percentage under Kruger’s criteria is 14% normal. A normal morphology assessment using the Kruger method correlates much more closely with male fertility. Studies have even shown that the percentage of eggs that are fertilized during in vitro fertilization (IVF) correlate well with the percentage of normal sperm seen.

Computer assisted sperm morphology

One problem that remained was human error -- the technicians performing the morphology would not evaluate semen samples consistently. There was often great variation from one day to the next or from technician to technician.

For this reason, at IVF1, we have opted to use a computer assisted system for determining morphology. The software, which measures individual sperm cells and shapes, was developed and validated by Dr. Kruger. We can always be sure that no matter who is performing the semen analysis, the results are going to be consistent from day to day.  In fact, we continue to perform our quality assessment by exchanging slides with Dr. Kruger’s lab to make sure that we are always in accordance with the gold standard.

A standard semen analysis is done under a microscope and can tell you how many sperm are produced, how many are moving, and how many have a normal appearance. Although a semen analysis will identify some couples with a lower chance to conceive, its overall ability to predict fertility is poor. There is a need for better sperm quality testing. One method to test sperm quality is to look for genetic changes within the sperm. This type of sperm quality testing is known as sperm epigenetic testing.

What is epigenetics?

Epigenetic modifications are changes that are made to the DNA that help the cell regulate which genes are “turned on” or activated and which genes are “turned off” or suppressed. An active gene will produce proteins, and a suppressed gene will not. Hundreds of thousands of different locations in the DNA can show epigenetic changes.

Sperm quality can be tested by looking at epigenetic changes. Scientists have identified epigenetic changes in sperm that are commonly found in individuals with infertility or couples who seem to make poor quality embryos during IVF. The more of these “bad” epigenetic changes found, the greater the chance that there will bd problems with infertility. Certain factors impact “bad” epigenetic changes in the sperm. For example, people who smoke, are obese, or are older tend to have more “bad” epigenetic changes in their sperm.

Sperm quality testing using epigenetics

One currently available test is pretty easy to do. A semen specimen is collected and sent to a special laboratory, and in a couple of weeks, the doctor will receive a report that will look something like the graph below:

The graph shows that men with infertility will often have lots of abnormal epigenetic changes. Men with normal fertility will often have few abnormal epigenetic changes.

What if the test comes back abnormal?

An abnormal test doesn’t necessarily mean that a pregnancy is impossible, but it may identify those who are more likely to have problems even if their semen analysis is normal. If a lifestyle factor is identified, such as smoking, then quitting may help improve fertility. In some cases, couples may choose to go directly to a more aggressive treatment such as IVF.

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SCSA stands for sperm chromatin structure analysis. Other names describing the same test are: sperm DNA fragmentation test, sperm chromatin fragmentation test.

SCSA Background

Recently, there has been increased emphasis on the evaluation of sperm quality. This is due, in part to the fact that a sperm test or semen test by itself is of limited value. Sperm counts, for example, fluctuate significantly from day to day in most men. When you think about it, sperm are nothing more than vehicles to transport DNA to the egg.

Since sperm are very small, a large amount of DNA must be “crammed” into a very small container. In order to accomplish this feat, the DNA is wound and twisted on itself and wrapped around blocks of protein. The combination of DNA and protein blocks is referred to as chromatin. Part of the function of the protein blocks is to protect the sperm DNA from damage during its long journey from where it is produced (in the testicles) to where it hopefully arrives (the egg). However, it seems that some DNA will remain susceptible to damage and that DNA can become fragmented.

How SCSA is performed

There are several different tests that have been developed to assess the percentage of sperm with significant DNA fragmentation. One test is called the TUNNEL assay. Another is called the COMET assay. The test that has received the most attention recently however, is called the SCSA or sperm chromatin structure analysis.

During the SCSA test, sperm are treated with a chemical to allow entry of a special dye into the sperm cell. The dye sneaks its way into crevices in the DNA molecule. In theory, sperm with fragmented DNA take up more of the dye. Then, using a procedure called flow cytometry, the sperm that took up lots of dye (the sperm with fragmented DNA) can be differentiated form the sperm that took up only a little dye (sperm with normal DNA). Finally, using a computer program, each sperm can be graphed out or the percentage of sperm with fragmented DNA can be determined.

Clinical significance of the SCSA test

Some of the early clinical data involving SCSA suggested that men with more than 30% of their DNA with fragmentation had extremely poor pregnancy rates (1% or less) even with aggressive techniques such as in vitro fertilization – IVF. Current data proves that this was not true!

The results of multiple subsequent studies were quite different than the original studies. In a Colorado study, 128 couples going through an IVF cycle had sperm frozen for SCSA. The pregnancy rate in patients with a SCSA showing less than 30% fragmentation (the normal group) was 62%. The pregnancy rate in patients with an SCSA greater than 30% (the abnormal group) was 81%. In the abnormal group, the average SCSA result was a fragmentation index of 40%.

Another study performed in North Carolina and since published in the journal Fertility and Sterility involved 100 couples undergoing IVF. SCSA testing was performed on the same semen specimen that was used for fertilization of the eggs. Nine of nineteen couples achieved clinical pregnancy when the DFI (DNA fragmentation index) was greater than 27%.

The best conclusions that can be made today about an abnormal SCSA test are:

• Whether fertile or infertile, all sperm-containing semen will have sperm with fragmented DNA.
• Individuals with a normal semen analysis can have an abnormal SCSA.
• A SCSA test result is very consistent over time, more consistent than a semen analysis. However, some factors such as a high fever or certain medications can cause an abnormal test. Certain steps in preparing for the test can affect the results of the SCSA.
• The best evidence to date suggests that people with an abnormally high percentage of sperm with DNA fragmentation have a pregnancy rate similar to those with a normal percentage of sperm DNA fragmentation when using techniques such as IVF.

Some final things to know

Currently, it does not seem that the SCSA test will help predict those couples who are less likely to get pregnant with IVF. It is also unclear who should have the SCSA test and who does not need it. Even if we believe that the test is correctly identifying couples with a lower chance for achieving pregnancy, there are no known treatments which improve the chance for pregnancy.

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Cap-Score™ Sperm Test

The main problem with the semen analysis is that it was not a very accurate predictor of fertility. Over the last few decades, there have been numerous attempts to develop a sperm test that would predict fertility more accurately. Unfortunately, there was not much success – until recently.  A new sperm test, known as the Cap-Score™ is the first test that actually measures a key function of sperm called capacitation.

Capacitation

Ejaculated sperm are not ready to fertilize an egg when they enter the vagina. In response to the dilution of semen in the vagina, the levels of a protein called FPP (fertilization promoting peptide) start dropping. This results in the sperm starting to undergo several changes, which are collectively known as capacitation.

During capacitation, the head of the sperm sheds some proteins and other molecules from its surface, this allows the mineral calcium enters the sperm more rapidly which results in increased energy production and then the sperm tail starts to beat more vigorously (hyperactivation). This may help the sperm power its way through the cells that surround the egg.

Finally, there is a small sac of enzymes at the top of the sperm head called the acrosome. During capacitation, the acrosome starts to become more unstable. These enzymes will be needed to dissolve the hard shell that surrounds the egg.

Unless a sperm undergoes capacitation, it will not be able to fertilize an egg.

Cap-Score™

As you might have guessed, some men may make sperm that are unable to undergo capacitation or have only a small percentage of the sperm that do so. The Cap-Score™ is a test that was developed to determine the percentage of sperm that undergoes capacitation in a certain amount of time.

By looking at people with normal fertility, scientists were able to determine that 35% of the average fertile person's sperm will undergo capacitation (Cap-Score™ of 35%). Those with a low Cap-Score™ – 27% or less – are likely to have fertility problems, even if there are lots of fast moving sperm. Data now shows that the the higher the percentage of sperm that undergo capacitation, the higher the probability for pregnancy.

What do I do if I have a low Cap-Score™?

Currently, we do not know of a way to improve the ability for sperm to undergo capacitation. The current recommendation for these couples is to not waste time and money with treatments that require sperm capacitation such as intercourse or intrauterine insemination (IUI). Data shows that even with several cycles of IUI, couples with an abnormal test have a lower chance for pregnancy. Instead, these couples should consider moving directly to IVF where the sperm can be injected directly into an egg to fertilize it via ICSI. This will completely bypass problems with capacitation.

Where can I get the Cap-Score™ Sperm Function Test?

You can do all of your sperm testing here at IVF1. Many tests are done here, while others like the Cap-Score™ will be sent to their lab for analysis.