Doctors monitor several semen parameters when assessing male fertility. During a lab test you will deliver your sample to the doctor or lab technician, who will analyze it on a microscope. Following your test you will receive a lab report with your scores. What do these numbers all mean? We’ll do our best to help you sort it all out. If you are planning to schedule a semen analysis, make sure to also read our article on preparing for a semen analysis. You may also want to check out our fertility quiz to identify risk factors and get personalized recommendations for how to optimize your fertility.
Fertility is all about probability. Out of the millions of sperm released into the vagina following sex only a handful even come close to the egg. Even these few have to be healthy enough to survive long enough in the female body for an egg to show up. So, when trying to conceive, the more healthy sperm you have, the better the odds that one of them will make it alive to the egg. However, it is important to remember that just one little sperm is all it takes, so even if you have a low count it is possible to get pregnant naturally although with reduced monthly odds.
The semen analysis measures a number of parameters that affect the chances of the sperm reaching the egg. Some of the parameters are indicators of sperm production and health (see How Sperm are Made) others relate the the quality of the semen and its ability to help sperm along the journey to the egg.
Parameters measured during a semen analysis
The World Health Organization (WHO) has compiled extensive data on each of these parameters for healthy men that were able to conceive following less than 12 months of trying. We have included the WHO “normal” range for each parameter, which we define as falling between the 5th and 95th percentile of healthy men. (WHO Guidelines for Semen Analysis)
This number tells you the approximate number of sperm cells present in your semen sample. It may be reported as the sperm concentration (millions of cells per milliliter of semen) as well as total count (millions of cells in the ejaculate). The total count is calculated by simply multiplying the sperm concentration by the volume of the ejaculate.
Male fertility basically comes down to a numbers game. Of course you really only need one good sperm cell to conceive a child. But your chances are much better if you’re armed with millions of good sperm cells. Thus the higher your sperm count, the more likely you are to successfully conceive.
WHO Normal Range (5th – 95th percentile): 15 – 213 million cells per mL
Sperm Motility (%)
It’s not only important to have high numbers of sperm cells present, they also need to be able to swim and accomplish their mission. The percent motility tells you the fraction of your sperm cells that are motile (swimming).
Some laboratory reports will break down this category further into sub-categories including rapid progression, slow progression, and forward progression, which quantify the speeds of swimming cells as well as their directionality (healthy sperm swim forward). These parameters are more difficult to quantify and can vary considerably based on the technician performing the analysis. Therefore these more subjective parameters are often ignored by physicians. The important metric to consider is how many of the cells are swimming at all.
WHO Normal Range (5th – 95th percentile): 40 – 78%
Semen Volume (mL)
The ejaculate volume is measured primarily to estimate the total number of sperm cells delivered to the female. However, an abnormally low ejaculate volume may prevent sperm cells from successfully navigating their trip through the female’s reproductive tract. An abnormally high ejaculate volume could be a symptom of an infection. Your doctor would likely order additional tests if suspecting that their many be an infection.
WHO Normal Range (5th – 95th percentile): 1.5 – 6.8 mL
Sperm Morphology (%)
Morphology denotes the fraction of your sperm cells that have a normal shape. Sometimes sperm heads or tails have an abnormal size or aspect ratio. Sperm cell morphology is typically only measured in cases where the couple is assessing their options for in vitro fertilization (IVF). Morphology has been shown to correlate with the chances of successful conception via IVF. However, for conventional intercourse or artificial insemination, the morphology parameter is basically irrelevant. For assessing your chances of conception via “the old fashioned way”, just pay attention to your count and motility.
WHO Normal Range (5th – 95th percentile): 4 – 44%
Your semen report will likely include several other parameters, which tend to be less important but still may affect your chances of conception or be indicators of your overall health:
pH: An acidic (low pH) semen sample may be indicative of a blockage in your seminal vesicles. A basic (high pH) semen sample may be due to an infection. If the pH is abnormal either way, your doctor will likely order additional tests. Normal Range: 7.2 – 8.0
Viscosity: Viscosity is a measure of how “thick” or “watery” the sample is. Highly viscous semen may inhibit sperm motility and make it more difficult for your sperm cells to reach the female’s egg. The technicians typically measure this parameter somewhat subjectively and will give you a score of Low, Normal, or High. Normal Range: Normal
Liquefaction Time (minutes): Fresh semen samples will “liquefy” over time due to enzymes in the sample that break down the gelatinous structure of the seminal fluid. This process helps reduce the viscosity of the sample and therefore improve the sperm cells’ ability to swim. Some doctors will measure how long the semen sample requires to fully liquefy, especially if an earlier test revealed a high semen viscosity. Normal Range: 15 – 60 minutes
Fructose (μmol per ejaculate):Don’t get too excited, but your semen sample is naturally somewhat “sweet”. Doctors measure Greater than 13 μmol per ejaculate.
White Blood Cells(WBC, 10^6 cells per mL): White blood cells (or “leukocytes”) are normally present in trace amounts in a semen sample. A high concentration of WBCs in your sample may be indicative of an infection. WBCs are a major force in your body’s immune system, so if you have an infection your body naturally makes more WBCs to help fight it off. Your doctor will conduct more tests if suspecting an infection may be present. Normal Range: Less than 1 million cells per mL
Vitality (%): Vitality measures the fraction of sperm cells that are alive. Sperm cells have a somewhat short life span, therefore a normal ejaculate will include some percentage of dead cells. Too many dead cells could indicate a problem with your plumbing. WHO Normal Range (5th – 95th percentile): 58 – 91%
Putting it together: How semen analysis measures male fertility
It is important to understand about the results is that the parameters are related. So you can’t look at anyone parameter in isolation. For example one might have a low sperm concentration (say 10 million) but have a large volume (say 6 ml) which would give a total count of 60 million which is well in the normal range. One could also have a high count but low motility or a low count but high motility.
On the male side, there is a correlation between the total number of healthy swimmers you have and the chance of conception. The equation to get the total number of swimmers is:
Sperm Concentration x Semen Volume x % Motility = Total number of motile sperm.
The WHO doesn’t give a reference range on this but its good to try to shoot for something above 20 million. Because this is a numbers game, that 10 million isn’t anything like an exact number – it only takes one strong little swimmer to do the job. Your chances will increase as your total number of motile sperm increases. A different guideline proposes the following recommendations for total motile sperm count:
Less than 1 million TMSC. This category represents severely low motile counts (also called severe asthenozoospermia). A doctor might recommend to use advanced assisted reproduction methods such as ICSI, which involves injecting sperm directly into an egg.
1 to 5 million TMSC. This category represents moderately low motile counts (sometimes just called asthenozoospermia). A doctor might still recommend assisted reproductive methods like IVF or IUI to achieve pregnancy.
5 to 20 million TMSC. This category means you’re low, but natural pregnancies are still likely within 2 years. A doctor might still recommend IUI to achieve pregnancy.
Above 20 million TMSC. This category means you’re “normal” in terms of motility. If you are still having trouble conceiving, other fertility factors besides motility should be looked at to see if the problem lies elsewhere.
It is important to remember that a semen analysis is a snap shot on a given day. For a true diagnosis the WHO manual recommends a minimum of two analysis a few days apart to get an average. Also counts can vary day to day and week to week based on a number of factors like how much you worked out, had sex, drank alcohol and sugary drinks, how hot it was and if you had a cold. All these things can impact the quality of your semen.
Houston, we have a problem. Now What?
An abnormal semen analysis is a big blow to the pride but it is not the end of the world. There are things that you can do and that your doctor can do to help correct the majority of the problems. Beyond impacting fertility, abnormal semen analysis can help diagnose more serious health conditions such as testicular cancer, so if you haven’t already done so, it’s a good idea to get checked out by a urologist who specializes in male fertility to help guide your next steps. We’ve done some research to pull together current medical research regarding male fertility to help you have informed conversations with your doctor, choose the treatment options that best suit you and give you tools to improve your fertility. Get personalized recommendations around risk factors that could be contributing to abnormal results.
Below are the most common diagnosis’s made from the semen analysis.
Asthenospermia – swimmers don’t swim: Asthenospermia occurs when the testicle is making sperm but they are not swimming. Major causes of reduced motility include: varicocele, poor diet, heat exposure, obesity, and toxin exposure.
Azoospermia – Zero sperm: Azoospermia is broken down into two camps. Obstructive, which means that there is something blocking the path and trapping sperm inside the testicle. An non-obstructive, which means that the body isn’t producing sperm to begin with. The treatment options, as you can imagine are quite different. To figure out what’s going on, a male fertility specialist may perform a physical exam, ultrasounds, blood work and perhaps a few other tests to diagnose the exact cause. Often, due to remarkable advances in technology and medical science, there are options to enable azoospermic men to successfully father children.
Oligospermia – Low Sperm Count: Oligospermia means that there is a low sperm concentration in the ejaculate. Generally, this means that something is impairing the testicle’s ability to produce sperm. Learn more about low sperm count.
Hypospermia (semen volume under 2mL) and Aspermia (no semen): Usually indicate some sort of plumbing problem; a complete or partial blockage or a condition called retrograde ejaculation. Depending on the underlying cause there are prescription medications or surgical procedures that can help treat the issue. For more severe cases where treatment is unavailable or ineffective, a specialist can retrieve sperm from the testicle for artificial insemination or IVF.
Teratospermia – Abnormal morphology:Abnormal morphology means that something is interfering the the sperm maturation process that causes a high number of them to develop abnormally. Abnormal sperm can have heads that are too big or too small, two heads or two tails or they can be missing key proteins that enable them to accomplish their mission.
A note from the author:
I’ve been so honored by all the readers who have shared their stories and questions. One of the best parts of my day is responding to your comments. Sometimes, there is a bit of a backlog and it can take me up to a week to respond, but I promise, I will get to your question. We are launching a new community — so I will be answering questions left there first.
In the meantime, I’ve been working on a couple of projects that might be of interest.
I would also invite you to check out our gadget section to see latest innovative products that have been developed to support couples who are trying to conceive. I have met the founders of most of these companies and believe in the great work they are doing to help people start their families.
Finally, I would like to send a word of encouragement to everyone who is on the path to starting a family. The journey can be scary, frustrating and at times very sad. You are not alone. Millions of people around the world are going through the same thing. Keep putting one foot in front of the other. Keep learning. Knowledge can empower you to find new doors to open.