Homepage Sperm testing: how to interpret the results
Category: DiagnosesJune 04, 2008 4:30 pm
There are many sperm tests available; some results will be more relevant to you than others.
Which results should matter to you? Well, it all depends on context of course, and to help you understand sperm tests better, I thought I would post about it below, by highlighting the 4 things we really want to know about sperm.
1. Can the sperm reach the egg?
First things first: the sperm have to reach the egg.
When a couple is having intercourse (or when donor sperm is placed on the cervix), sperm will exposed to the somewhat acidic vaginal milieu. It isn’t a particularly hospitable place for sperm, and many won’t get past this stage. In fact, 99% of sperm will die within 20 minutes.
We want some sperm to be well protected for there to be a chance of pregnancy. Fortunately, they are safer when surrounded by cervical mucous, and by the seminal fluid itself. Therefore we like to see a good volume of seminal fluid, usually between 1.5 and 5.0cc, to be confident that the sperm will be safe enough to have that chance to swim up into the uterus and beyond.
Still, many sperm won’t make it. Probably about 90,000 sperm will get up into the uterus, from an average 90 million or so in the ejaculate. This is why the number of sperm is so helpful, measured as the concentration, usually 20 million/ml or more. When you start with more sperm, it becomes more likely that enough will arrive at the final destination.
Of course, they won’t be able to swim anywhere if they don’t have good motility (usually >40% have normal motility) and they won’t be able to swim quickly and in a straight line if they have an abnormal shape, measured as morphology (usually >30% have normal morphology).
If all four parametes above are normal, it becomes highly likely that the sperm have the ability to reach eggs. Lower-than-average numbers leads us to wonder if the sperm are even being given the chance fertilize eggs at all.
2. Can the sperm penetrate the egg?
Once they get arrive at the end of the fallopian tube, sperm have to stick on, and burrow their way into, the egg. This ability stick-on-and-burrow is not measured by the usual sperm tests (though motility and morphology correlate somewhat with this ability). To find this out with greater accuracy, you will need to do sperm penetration and binding assays. Not every clinic is able to offer this extra level of testing. And to be fair, the most precise way of all to measure this ability is to do IVF, where the lab can watch your sperm try to enter your partner’s eggs.
3. Is the sperm carrying good DNA?
At the end of the day, sperm is just a vector for DNA. When a sperm swims well and penetrates an egg, it will all be for naught if the DNA it carries isn’t able to do the job and help to create a healthy embryo.
The most common way to approximate the quality of the DNA carried by sperm is to do a karyotype, in which we test the man’s DNA in his blood cells or cheek cells. No, a karyotype isn’t the same thing as the DNA in the sperm -errors can be introduced during sperm development that are not found in any other cell in the body- but it is a reasonable place to start. We will also test the man for specific genetic errors (such as cystic fibrosis or Y microdeletions) when clinically indicated.
Yes we would rather test the DNA in individual sperm, but current technology limits our ability to do so. “Five probe FISH analysis”, for example, looks at individual sperm, but it is a highly specialized investigation that only a few centres in North America offer. Though I offer it to some patients, its value seems to be limited and in most situations, the karyotype will be sufficient.
4. Are the epigenetics of the sperm’s DNA intact?
Until recently, we though that our genetic health was determined solely by DNA, but now we realize that how the DNA is held together (imprinting) is critically important too. If the DNA is not “packed together” properly, it may be not interpreted properly….and a variety of different problems (including lack of pregnancy) may result.
We test the epigenetics of sperm through DNA integrity assays, also known as a DNA fragmentation index (DFI) or sperm chromosome structure assay (SCSA). These have proven to be very useful tests in a modern clinical practice when male factor subfertility is suspected.
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Here is a summary of the most common tests that we will order for men when confirming their fertility potential. Not all tests are appropriate for all men; ask your doctor which might be right for you.
Standard semen analysis:
Volume
Count
Motility
Morphology
Newer sperm tests currently available:
DNA fragmentation
Sperm penetration/binding assays
Direct DNA (FISH) analysis
Autoantibodies to sperm
Frequently ordered mens’ tests:
Hormonal screen
Autoimmune screen
Karyotype and Y microdeletion
Physical exam/scrotal and transrectal ultrasound to look for varicocele and other testicular anomalies
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Perry
Hello,
Our daughter was born via ICSI and she is now 14 months and fine. I had very high DNA fragmentation - around 60% at the time.
Recently, we became pregnant naturally! Unfortunately, we just found out that the baby has down syndrome. Despite Dr.s telling me it is not a result of DNA Fragmentation I’m not so sure. My last test I was around 70%. I am 43 and my wife is 38. Really would appreciate your opinion.
TGH replies:
Dear Perry
Trisomy 21 (Down’s syndrome) can affect any couple, at any age, though we have known for years that risks increase with maternal age.
More recently, it has been suggested that risks increase with paternal age as well.
That said, we have not yet made specific risk assessment tables related to paternal age and/or DNA fragmentation. We just don’t know how tight these associations are yet. A New York Times article captures the concerns, but not really what we should be doing about it…or how we should be counselling patients.
I would suggest that if you and your partner had intentions to have more children, that you do so. But if you need more information, you might consider seeing a genetic counsellor.
TGH
Nataliya
Hello Dr. Hannam,
We have been unable to find a semen analysis lab that would take our test. Our doctor didn’t give use any suggestions, and only said “to take a test in any lab”. Making appointments has also been unsuccessful for us, labs on the phone say one thing and then do not take our test when we try to submit it,… anyways, can you suggest a lab, preferably open on saturday, somewhere in Richmond Hill or Woodbridge?
thank you
TGH replies:
Dear Nataliya,
I asked Michelle, my manager of clinical operations:
“The couple should be advised to go online to either Gamma Dynacare or LifeLabs and look up the patient service locations. They need to call prior to going to confirm that samples are accepted and if there are certain days and times that samples are accepted”.
RR
Dr. Hannam,
My husband and I are 31 years of age. We have conducted several preliminary infertility tests. Two results were abnormal: my husband’s semen analysis - numbers are there but poor morphology (75% abnormal). Also I have had 2 FSH tests - one at 11.2 and the other 10 (borderline values). My RE didn’t seem too concerned about those FSH values. I’ve tried clomid for 2 cycles with timed intercourse - no success there. What do you recommend as our next step?
Any suggestions are very much appreciated.
RR
tHannam
Dear RR
25% normal morphology is low. But did he do his test at Mount Sinai? Interesting thing: the way MSH Urology processes samples, morphology often comes out low-normal or low. My advice:
*ask to have the test repeated, along with a DNA fragmentation assay.
*your husband could take antioxidant vitamins. A list of suggestions for improving sperm quality is here.
*for the final word on sperm, you need to speak to a Urologist. Ask for a referral to MSH Urology to see if more can be done.
In the end, 25% normal morphology may be amenable to intrauterine insemination cycles (IUI). For most programmes, IUI will have about a 10% overall success rate (ranges are 7-22.5% depending on the clinic and other factors) and IVF about 32% (range 20-78% in your age bracket) per cycle. Yes, IVF has the better success rate, 3 or 4x better, but many people will try IUI first because it is less interventional and less expensive.
I’m sure you are worried about the high-normal FSH levels. I strongly recommend making sure you know the results of the other tests of ovarian reserve. If it is indeed true that you don’t have a great number of eggs, well, that is not ideal, but your age alone would be highly suggestive that eggs are, if not numerous, then of good quality.
Best,
Tom Hannam
counselling service
counselling service…
Loved the information here I’ll have this bookmarked and will be back to read more….
Kathryn
Hello Dr. Hannam,
We have been trying to conceive for 13 months. Two semen analyses completed 6 months ago were excellent (approx. 200 million total, 80% motile). We tried IUI last month again this cycle. The semen results associated with the IUIs were 45 & 60 million total, 40 & 50% motility, and 20 & 30% morphology. Our RE says these numbers are normal and not concerning. However, we are very concerned about the sharp decline in quantity and quality. Do you have any thoughts about what could cause this to happen and what we might to do restore his sperm count and quality?
Thank-you
TGH responds:
Dear Kathryn:
Sperm counts change dramatically from month to month, most of the time we do not know why.
You can ask your R.E. if there are significant white blood cells—this can be associated with a subclinical prostate infection, easily treated with antibiotics and can account for sudden changes such as those that you describe.
More commonly, however, we assess “sperm quality” through not just one test, but multiple tests. Perhaps a third IUI attempt would be in order, and then a longer discussion with your R.E. as to whether or not significant male factor subfertility is suspected.