Semen Analysis Overview
When a couple is having trouble conceiving, the first step in the evaluation should be a comprehensive semen analysis. In 60% of all couples experiencing infertility, a male factor is involved (40% primarily male and 20% combined male/female.) The comprehensive semen analysis is a noninvasive test, that yields an amazing amount of information when correctly performed.
When should I do a semen analysis?
85% of couples will conceive within a year of having regular intercourse without using contraception. This means the man is ejaculating in his partner’s vagina and not avoiding the right time of the month, (but not necessarily timing it precisely with ovulation prediction kits either.) Using the withdrawal method, i.e. ejaculating outside, is counted as contraception, though it does have a high failure rate when being used as a contraceptive technique.
A couple is considered subfertile if they do not achieve a conception with 12 months of attempts (not necessarily consecutive.) However, when a woman is 35 or older, since fertility rates begin to diminish, it is usually thought prudent to begin an evaluation after six months of attempting to conceive. Thus, if a couple where the woman is under 35 has not conceived in a year, or where the woman is over 35 has not conceived in 6 months, a semen analysis should be performed and an infertility evaluation started.
How long does it take to make sperm?
Sperm are made continuously, like on an an assembly line and the sperm you are ejaculating today started along the line three months ago. The analogy we often use for our patients is that of a cookie factory. The cookies (sperm) are made on an assembly line and then placed into a holding area (the ducts and glands that line your reproductive tract). How often the holding area is emptied (ejaculate) does not affect the production line. If you empty the holding area more often you will have fewer cookies, but they are fresher. If you empty it less often, you will have more cookies, but they are less fresh. (However, men are not assembly lines, and we don’t always empty out our holding areas when we ejaculate.)
Why is production time important?
This three month production has two significant implications.
The first, is that anything you do, affects the sperm for the next three months at least. This includes good things, as well as bad (smoking, drugs, hot baths or saunas).
Second, there is often a four to six month delay between treatment of the man and any changes that we see in the semen analysis. Since the evaluation of the woman may take several months, it is recommended that a comprehensive and accurate semen analysis be performed at the outset. Treatment of the man can then occur at the same time as treatment of the woman, and there will be no unnecessary delay once the woman’s treatment is completed.
What happens if there are problems found in the semen analysis?
The same man may have significant variability in his semen analyses. Thus, it is always recommended that more than one semen analysis be performed in order to get a baseline. Some men have such significant variability that more than two analyses must be done to establish his norms.
If there are persistent abnormalities detected in your semen analysis, you should consult with a urologist specializing in male infertility. The urologist will identify any problems and then address them in order to maximize the quality of your semen. This may reduce the need for more complicated interventions for the female partner. It is also important to rule out significant medical problems that may contribute to a poor semen analysis. Therefore, the most important first step in any man’s evaluation is the semen analysis.
Two thirds of the time, the specialist can work with you to make a significant improvement in your analysis, but one third of the time no reversible causes are found. In these cases, your fertility team (including your wife’s specialist) will need to work around them if possible.
One key thing to know is that there is no specific, magic number in the semen analysis of men whose partners will get pregnant and those who won’t. The partners of some men with a very poor semen analysis may conceive easily. The partners of some men with an excellent semen analysis may experience difficulty. However, men with good semen analysis results will, as a group, conceive at significantly higher rates than those with poor semen analysis results.
The semen analysis will help determine whether there is a male factor involved in the couple’s sub-fertility. If that’s the case, we’ll recommend an evaluation. Some findings of the semen analysis suggest certain specific potential problems. For example, an increased white blood cell count may indicate infection or inflammation. However, other abnormalities in many of the main parameters are non-specific. For example, there are a number of different causes for a decreased sperm count or diminished sperm movement. A few of these causes have other serious medical implications. A thorough evaluation helps determine the cause of an abnormal semen analysis and rules out medical problems.
What is semen?
Semen is the fluid that a man ejaculates. This fluid is produced at several different sites in the body. The sperm within the semen are the cells that actually fertilize the egg and are therefore the most important to assess. However, the sperm account for only 1% to 2% of the semen volume. (In fact, only 5% of the total fluid comes from the testes, which is why men with no sperm in the ejaculate, including after a vasectomy, cannot tell the difference either in the feeling they have when they ejaculate, or in the appearance of the ejaculate itself.) Problems with the surrounding fluid may also interfere with the movement and function of the sperm so both the sperm and the fluid must be tested.
Volume is a measurement of the quantity of the ejaculate. How much fluid is there?
What units are used?
The semen analysis is measured in milliliters (ml) which is the same as cubic centimeters (cc). For reference, a teaspoon equals 5cc.
What is normal volume?
Normal volume is two cc or more.
What affects volume?
The volume may be low if a man is anxious when producing a specimen, if the entire specimen is not caught in the collection container, if there are hormonal abnormalities, or if there are ductal blockages.
Concentration/count is a measurement of how many million sperm there are in each milliliter of fluid.
How is concentration/count measured?
There are various techniques for obtaining this number. Some prove to be more accurate than others. The most accurate method uses one-time-only use slides. These slides have a built in cover that allows only an exact amount of semen into the chamber. Thus the depth is consistent. Reusable chambers change in depth as they are cleaned and reused.
Measuring concentration takes surprising expertise, both in preparing the slides and reading them. Problems include:
- The right slides and microscopes must be used.
- Sperm move in and out of fields.
- The ejaculate is not homogeneous, and some parts may have higher concentrations than others. So, it is important to measure multiple fields, and then average them.
What is normal concentration/count?
Average sperm concentration is more than 60 million per milliliter (>60 million/cc). Counts of less than 20 million per milliliter (<20 million/cc) are considered sub-fertile.
What affects concentration?
Concentration depends on how many sperm are made and ejaculated, and how much fluid is made and ejaculated.
Men with low sperm production will of course have low concentrations no matter what the volume. (Please see the section for Male Infertility for what factors can affect production.)
Some men make high volumes of semen. This dilutes out the sperm, and causes the man’s concentration to be lower. Two men who ejaculate the same number of sperm, will have different concentrations if they ejaculate a different volume. Thus, an expert will look at the volume as well as the concentration to assess sperm production.
Motility describes the percentage of sperm that are moving. In even the best specimens, many sperm are not moving. The (immotile) sperm may either be dead or just not moving. This actually is a significant difference, especially in specimens with a 0% motility. (See Viability, below.)
What units are used?
Motility is measured as a percentage. If all the sperm are moving, motility is 100 or 100%. If no sperm are moving, motility is 0%. Most specimens are in between.
How is motility measured?
The sperm are placed on an etched slide, and numerous boxes in the grids are counted. Counts are kept of the moving sperm and the immotile (non-moving) sperm. The percentage of moving sperm (the total moving divided by the total number of sperm) is calculated. Since specimens are not the same throughout (i.e. they are not homogeneous) sometimes multiple areas of the slide must be examined to come up with an average. The measurement is tricky because the moving sperm are of course moving in and out of the boxes.
What is normal motility?
Fifty percent or more of the sperm should be moving.
What causes low motility?
Low motility can be caused by issues with production, as well as issues occurring within the ducts that store and transport the sperm. For example, infections may decrease the motility of the sperm in the ejaculate, even if they were originally produced with a good motility.
The Forward Progression parameter looks at the quality of the movement itself, when looking at the sperm that are moving. In other words, are they “fast swimmers” or “slow swimmers?”
What are the units?
Forward Progression (FP) is measured on a scale. The World Health Organization (WHO) uses a scale of 1-4. The table below reviews what each number is meant to represent. Usually it is reported as a single number, which is the average FP.
|1||Movement, None Forward|
|1+||Occasional Movement of a Few Sperm|
|2+||Slow, Directly Forward Movement|
|3-||Fast, Undirected Movement|
|3||Fast, Directed Forward Movement|
|3+||Very Fast Forward Movement|
|4||Extremely Fast Forward Movement|
What are the implications of forward progression?
It is crucial that this number be reported. It is important not only to measure what percentage of the sperm are moving (motility) but also how well they are moving (forward progression) to get a sense of the sperm’s overall movement. If a man has a high motility, but a low forward progression (i.e. a lot of sperm just wiggling back and forth in place) the sperm will not be able to make their way through their partner’s reproductive tract and fertilize an egg, because they can’t move forward. A man with a lower motility, but a great forward progression, would have fewer sperm moving, but they would be moving forward quickly, which would give them a better chance of fertilizing an egg.
Morphology describes the shape of the sperm. The sperm are examined under a microscope and must meet specific sets of criteria for several sperm characteristics in order to be considered normal. Most commercial laboratories will report WHO morphology (use World Health Organization criterion). A more sophisticated, and more useful way of assessing shape, called Strict, Kruger, or Tygerberg Morphology (see link below) is also used by speciality labs. Strict is much more time consuming to perform, and takes a lot of time and experience to master, so it is usually not used by commercial or hospital labs.
What units are used?
Morphology is measured as a percentage. If all the sperm are normal, morphology is 100 or 100%. If no sperm are normal, morphology is 0%. Most specimens are in between.
What is normal morphology?
WHO (World Health Organization) Morphology: Using WHO criteria, 30% or more of the sperm should be graded as normal. For a sperm to grade as normal, it does not have to be as perfect as the Strict Morphology (see below.) Thus, for the same specimen, the WHO Morphology will by necessity always be higher than the Strict Morphology.
Strict (Kruger, Tygerberg) Morphology: Traditionally, 14% of sperm should be graded as normal, in order to be considered a normal Strict Morphology. However, many labs use 4% as the cut off.
What are the implications of a low morphology?
It is most important to state upfront, that having a low normal morphology (which translates to a higher number of abnormal sperm) does NOT correlate with increased chances of an abnormal baby. It can just make it more difficult for a couple to conceive.
Some couples conceive, and have normal babies at the same rate as other couples, even with a 0% normal morphology.
Rarely, a man will have all of his sperm shaped abnormally in one particular manner, and this may have genetic implications.
It is currently felt that if the Strict Morphology is <4, if IVF is done, the sperm should not just be left in the “dish” with the eggs (conventional IVF), but that an individual normal sperm should be injected into each egg (ICSI).
Total Motile Count (TMC)
The Total Motile Count (TMC) is the number of moving sperm in the entire ejaculate. It is calculated by multiplying the volume (cc) by the concentration (million sperm/cc) by the motility (percent moving). There should be more than 40 million motile sperm in the ejaculate.
What units are used?
Total motile count is measured simply as a number, reported in millions. For example a TMC of 53 means that in the man’s entire specimen, the whole ejaculate, he is calculated to have 53 million moving sperm.
Why is this useful?
Some men have a very high volume, and still produce good numbers of moving sperm. However, their concentrations may be low, because the sperm are found in a lot of fluid, i.e. the fluid is diluting out the count. Some men may have excellent concentrations, but low motilities, so be very few moving sperm in the ejaculate. TMC accounts for the all three of these parameters, and gives a value that is useful in making clinical decisions.
What is a normal Total Motile Count?
There is some debate regarding this number. However, 40 million moving sperm in the ejaculate is considered the low end of normal.
What are the implications of a low Total Motile Count (TMC)?
TMC is a very valuable parameter. It helps specialists make clinical decisions. If the TMC is over 10 million, there is a reasonable chance that taking the processed sperm and placing them directly into the uterus (IUI or intrauterine insemination) will be successful. Most specialists feel that if the TMC, after maximizing the man’s sperm production, is less than 10 million, that in vitro fertilization (IVF) is indicated.
Some men may produce antibodies to their own sperm. These antibodies may decrease fertility rates in a number of ways. They may impede the movement of sperm through a woman’s cervical mucus, inhibit the binding of a sperm to the egg, or inhibit its penetration into the egg. Men who are most at risk for developing antibodies are those with previous testicular and epididymal infection, trauma, surgery, or large varicoceles. The presence of these antibodies is often not predictable from other semen parameters or from the man’s history.
Many parameters can be measured but the most important are: 1) Round Cell Concentration, 2) White Blood Cell Concentration, and 3) Viscosity.
Round Cell Concentration
Besides the sperm, there are often other cells in the semen, seen under the microscope. Round cells can be immature sperm, debris (junk), or white blood cells (WBC’s). This number is usually reported as a concentration of round cells, ie how many round cells there are, in millions, per cc. of the ejaculate. Round cell concentrations of greater than one million per cc, may be significant (see below.)
White Blood Cell Concentration
Of the round cells found in the semen, it is felt that only if increased numbers of WBC’s is considered significant.
White blood cells are considered significant if more than one million are found in each milliliter of the ejaculate. However, white blood cells cannot be differentiated from the other round cells normally found in the semen (debris and immature sperm) without special staining. Thus, if more than one million round cells are found in the ejaculate, a portion of the ejaculate should be specially stained to look for an increased number of white blood cells.
A high WBC concentration may be an indication of either infection or inflammation, which can have a negative impact on the sperm.
If the white blood cell count is elevated, semen cultures should be performed on a subsequent specimen. Unfortunately, the semen culture cannot be performed on the original specimen as it must be the first step performed on the specimen in order to keep it sterile.
When a man ejaculates, the fluid is clumpy and viscous (thick). However, when it is exposed to body temperature (either by being in a woman’s vagina or warmed in the laboratory) enzymes that are present in it, break down certain proteins. This makes the fluid runny and non-viscous (thin). Some men have thick semen even after the semen has been at body temperature for greater than an hour. This is called increased viscosity.
Increased viscosity can make it more difficult for the sperm to break through the semen fluid, and make their way through their partner’s reproductive tract, and ultimately fertilize an egg.
Increased viscosity may indicate an infection, and cultures should be performed.
If a man has persistently increased viscosity, it may be worthwhile to wash the sperm, to separate the sperm from the fluid. Then it is put directly into his partner’s vagina (intrauterine insemination or IUI).
In certain situations, specialized tests are needed. These depend on the findings at the time of the analysis and can often be performed on that specimen. Only a specialized laboratory will be able to perform these tests appropriately and accurately.
Even if no sperm are seen on the test slide, the sperm count may still not be zero (as there may be very low numbers of sperm in the ejaculate). This has very important implications as it may determine if the couple can conceive using advanced reproductive techniques. This must be assessed by spinning down the specimen so that any sperm that might be in the semen are concentrated in a pellet on the bottom of the tube. This pellet is then meticulously and exhaustively examined to see if any sperm are found.
If sperm are found, it is important to consider freezing (cryopreserving) them for later use. For men with very low counts, often there are no sperm in a particular specimen. If a couple is doing an in vitro fertilization, requiring one live sperm per egg, having frozen sperm as a backup is crucial, in case there are no sperm in the man’s ejaculation on the day they retrieve his partner’s eggs.
Sperm may be alive, but not moving. A specialized staining technique is used to determine what percentage of the sperm are alive and is indicated when the motility (percent moving) is less that thirty percent.
Some men have no moving sperm in their ejaculate. However, if some are found to be alive, they can actually be injected into his partner’s egg.
The initial viability testing done on a particular specimen kills the sperm on the slide. Specialized testing can be done on the specimen the day sperm are needed to inject into eggs, which do not kill the sperm, but just differentiate which are alive. (Only alive sperm can lead to fertilization when injected into an egg.)
The initial viability testing is done on a semen analysis, in order to help predict how many living, even if not moving sperm, a man can be expected to have in his ejaculations.
In men with no sperm or very low numbers of sperm in the ejaculate, it is important to determine whether the sperm are not being produced at all, or whether they are being produced but are blocked from “getting into” the semen. A fructose test can help differentiate between these two problems. Fructose is only made in certain glands, the seminal vesicles, which may be absent in men with missing or incomplete ducts.
Post-Ejaculatory Urinalysis (PEU)
Some men ejaculate all or part of the sperm backward into the bladder. This can be detected by having a man ejaculate and immediately afterward urinate into a separate cup. The post-ejaculatory urine is then centrifuged to see if any sperm are present.
Sometimes, medications can be used to try to convert a man’s retrograde (backward) ejaculation, to forwards.
The purpose of sophisticated semen analysis testing is to identify if a man has issues that are contributing to the couple’s infertility.
More than 50% of men who have a male factor infertility will have a treatable cause14. These factors include varicoceles (dilated veins in the scrotum), infections, hormonal abnormalities, abnormalities in the seminal fluid, ductal blockages, and difficulties with erections and ejaculation. When these conditions are treated, either through medication (hormones or antibiotics) or surgery (varicocelectomy, vasal reconstruction, repair of a blocked ejaculatory duct), a man will often see a significant improvement in his semen analysis.
Those men with poor semen analyses whose conditions are not treatable may still have the option of using advanced reproductive techniques to achieve a pregnancy, including our Extended Sperm Search & Microfeeze procedure. Even those men with no sperm in the ejaculate may be able to have some living sperm procured from them through other methods and achieve a pregnancy using advanced reproductive techniques. Those few men who produce absolutely no sperm at all will have this information in order that they can explore other options.
This may sound like a foolish question, however, it is clearly important that you produce and transport (if necessary) your specimen in the way, that allows the results to be standardized.
For how long should I abstain (not ejaculate)?
The standard period of abstinence is 48 hours. Your semen analysis is being compared to other men with the same time between ejaculations. It does not matter how you achieved your previous ejaculation (through masturbation, intercourse, or other sexual activity).
In theory, if you abstain for longer, you will have more older sperm, (i.e. a higher concentration, but lower motility and forward progression.) If you were to abstain for a shorter period, you would have fewer fresher sperm, (i.e. a lower concentration, but higher motility and forward progression).
So, it is important that you abstain properly, which again is 48 hours.
How do I get it all in the cup?
Since most men don’t regularly ejaculate into cups, this can be tricky. First of all, you should open the cup prior to beginning to produce your specimen. The air hitting the cup will not contaminate it in any way.
Ideally, you would produce the specimen standing up or sitting. If you are lying down, the specimen will probably run out of the cup. If you lose some of the specimen, you may scrape it off your leg, penis, or abdomen, but do not scrape it off of the floor.
Where should I produce the specimen?
Ideally, you would produce the specimen at the lab performing the test. If not, you should try to pick a lab that is within an hour of your house. If you do need to produce it at an outside site, make sure you keep it at body temperature until it is delivered to the lab. Do not refrigerate it or heat it. Ideally you would keep it in a shirt pocket, with a jacket over it.
What happens if I can't produce a specimen under pressure?
First of all you will not be alone. This is a common phenomena. Many men cannot produce a specimen at the hospital or laboratory. Here are a few options:
Remember that this is not life or death. If you cannot produce a specimen this time, you may find you can do it the next time. You can always reschedule! It does seem to get easier over time, as men lose their inhibitions the more often they have to produce a specimen “on demand.”
I can’t even get a good erection.
This is also a common phenomena. You have a few options:
- You can just try again another day. (see above)
- If the laboratory is run by a physician (like ours) you can ask to see if you can get some help from a pill (Viagra, Cialis, Levitra, or Stendra). These are safe, unless medically contraindicated (which is quite unusual, and almost always applies to men on a class of medications called nitrates). They are not addictive. They do not have any affect on the sperm, or on your ability to get an erection or produce a specimen in the future. Just knowing it is available sometimes relaxes men.
- If you and your partner are comfortable, some labs, (like ours) will allow you to bring your partner in the room with you. Many men find this makes getting an erection and producing a specimen more difficult, but some men find it makes it easier.
I don’t masturbate, so I can’t produce a specimen.
The vast majority of men, partnered or not, masturbate. However for personal, or cultural reasons, some men never learn how. Also, some religious practices forbid men from masturbating, even as part of fertility evaluation and/or treatment.
The most common solution to this problem is to use a specialized condom with intercourse. This condom is specially treated so that it does not kill the sperm. (Many condoms have spermicides included). After ejaculation, achieved with intercourse, the condom is closed with a twisty, and placed in a sterile cup. It is then brought to the lab. (See instructions above.) Some couples prefer to produce the specimen through intercourse at the laboratory. This is of course only possible if they have a private room with a lock!
Some religions also prescribe that the condom has at least a pinhole in it, so that even if highly unlikely, conception is possible through that particular ejaculation.
FINDING A SEMEN ANALYSIS LABORATORY
Semen testing is a sophisticated and technical field. An improperly or incompletely performed semen analysis may miss significant problems. Unrecognized problems may unnecessarily delay a man's treatment. Unlike many other lab tests, a semen analysis relies completely on the expertise of those performing it. Make sure the lab has sophisticated protocols and well-trained, specialized technicians.
Most general labs (commercial and hospital) are not able to do an accurate and sophisticated analysis. The things to look for when choosing a semen analysis laboratory include:
In order to do an accurate and complete semen analysis, the laboratory staff must not only receive specialty training, but continue to do a high volume of the same test in order to keep proficient. At many commercial labs, staff is not trained adequately, or experienced enough, to get reliable and reproducible results, even for the basic tests.
In order to get accurate results, the specimen must be processed within one hour of collection. If not, the measurement of the movement of the sperm may be extremely inaccurate. Ideally, you would have the option to produce your specimen at the lab. With any lab you use, make sure that the analysis is performed on site, and immediately when received (especially if they do not give you the option of producing it on site.) Sometimes labs act as collection points and the specimen is actually shipped elsewhere for evaluation. Always check on the report as to when your specimen was actually processed. All specimens should be fully processed within one hour of the time you produced it.
Thorough, Complete, Sophisticated
As a semen analysis is being performed, certain findings may indicate the need for additional tests. Most commercial laboratories do not have the ability to do these tests. They may not be able to do them. They may not know they should be done, or they may not be allowed to do them without an additional prescription from your referring physician. Ideally, you should use a laboratory that has the capability to do complete initial testing as well as the flexibility, knowledge, and expertise to do the appropriate follow-up testing on the same specimen.
Comfort and Convenience
In order to maximize your results, it is important that you are as relaxed as possible. It is preferable that the specimen be collected at the laboratory itself in a comfortable room that is meant specifically for that purpose, with a lock, appropriate materials, and no time pressures!
At Maze Health, we are committed to state-of-the-art medical and scientific expertise.
- We perform all semen analyses within one hour of production.
- We perform the necessary secondary or additional testing on the same specimen. This maximizes the information obtained from the semen analysis and will limit the number of semen analyses you will need.
- We offer weekend and evening appointments.
- We give you the option of producing a specimen at home or in the office. Our private collection rooms are comfortable and equipped with appropriate materials.
- We communicate your results promptly and thoroughly to your doctor, helping you and your physician create an appropriate plan in a timely manner.
If you’re interested in having a semen analysis, or if you have questions we’ve not answered here,
PLEASE CALL MAZE AT 646-380-2600 FOR AN APPOINTMENT
or contact us for more information. We’re experts in male sexual and reproductive health.
Last updated: November 2021