General information on sperm diagnostics
Even a simple physical examination consisting of an assessment of secondary sexual characteristics (such as physique and hair growth), as well as palpation of the testicles, may provide the examining physician with some initial idea regarding the cause of sterility. However, the most important test is the sperm analysis (spermiogram), accompanied in some cases by determination of the DFI (sperm DNA fragmentation index).
Testing the quality of semen includes determining the concentration, motility and morphology of the sperm (percentage of normal sperm forms).
HALO test, SCSA test
Additional information can be obtained with further tests which are used to detect the presence of molecular breaks in the genetic material in the heads of the sperm.
The spermiogram serves as a basis for the diagnosis of possible fertility problems in men. It involves assessment of various characteristics of the ejaculatory fluid (semen). However, the most important characteristics are as follows:
- pH level,
- Sperm concentration (in million sperm/ml),
- Morphology (percentage of normally formed sperm cells)
- and motility (movement, expressed as a percentage).
Normal ranges according to World Health Organisation (WHO) criteria:
Volume 2.0 ml or more
Sperm concentration >=20 million/ml
Total sperm count >=40 million per ejaculate
Motility (movement) >=50 % with forward progression or >=25 % rapid linear motion
Morphology >=30 % with normal form
The following is evaluated in addition:
White blood cells <=1 million/ml
MAR test < 10 % spermatozoa with adherent particles
Liquefaction time 30 minutes, max. 1 hour
Odour similar to the odour of a horse chestnut flower
Other tests (as required):
Proportion of living sperm cells 75 % or more vital cells, which are not stained in the eosin test
Morphology is commonly evaluated according to what are known as “Kruger’s strict criteria” or “strict criteria”. According to these criteria, the spermiogram is still considered to be normal with a proportion of malformed sperm cells of up to 85 %.
In some cases, spermiogram findings can fluctuate widely. Therefore, tests should be carried out at intervalls of at least two months (ideally three). The testicles need about this amount of time to form new sperm. Patients should abstain from sexual activity for at least 3 and no more than 5 days before the test.
Unfortunately, the differential microscopic analysis of sperm quality does not always permit the precise assessment (prognosis) of a man’s fertility.
SCSA test, HALO test
While the spermiogram is the simplest test, it only provides partial information.
Increasing numbers of studies in the international literature indicate that the proportion of sperm with chromosome breaks within the genetic material may be of great significance not only for fertility but also for the risk of miscarriages. However, this so-called fragmentation index (FI) cannot be determined with a normal spermiogram (which is a microscopic test for sperm quality).
The HALO test or the SCSA (sperm-chromatin structure assay) can be used to determine the fragmentation index. Knowing the sperm DNA fragmentation index in addition, can be helpful in ensuring that an appropriate fertility treatment is selected from the outset. Months of therapy, which retrospectively may prove to have a low success rate, can therefore be avoided. One reason for this is the occurrence of breaks in the genetic material contained in the sperm, also known as fragmentations. An increasing number of women are experiencing a reduced chance of becoming pregnant by normal means.
Up to 25 % of men with normal spermiogram findings exhibit a high proportion of sperm cells with fragmentations. In these cases, treatments such as the introduction of semen into the uterine cavity (insemination) or test tube fertilisation methods (IVF/ICSI) may be indicated. Because breaks in genetic material cannot be detected with a “normal” spermiogram, an additional test is required in the form of what is known as the SCSA or HALO test. We perform the HALO test because this is less complicated and more cost effective than the SCSA test.
With the HALO test it is possible to recommend a tailored therapy at the right time. This may in certain circumstances save time and costs.
The HALO test costs 180.00 Euros. To date, neither statutory nor private health insurance companies are reimbursing the cost of this test.
The DNA fragmentation index (DFI) provides information on the prospect for a successful outcome for the different treatment methods. The evaluation hereby involves the assessment of the sperm alone:
DFI 0 – 15 %: Pregnancy by normal means appears possible.
DFI 15 -25 %: Pregnancy by normal means is possible, but there may be an increased period of time before pregnancy occurs. Patients who have already been trying to conceive a child for an extended period of time should at least consider insemination therapy (semen implantation). If the woman has additional problems or is older, IVF (in-vitro fertilisation) is advisable.
DFI > 30 %: Pregnancy by normal means or by insemination appears improbable. The success rate can be improved by IVF (in vitro (test tube) fertilisation).
DFI > 50 %: Pregnancy with IVF is improbable. Intracytoplasmic sperm injection (ICSI) offers better prospects.
DFI > 60 %: Very limited success rates; ICSI or donor sperm offer the only chance.
The recommendations listed here come from studies conducted by various working groups in recent years and serve exclusively as recommendations.