1.570 
The diagnosis of normozoospermia refers to semen that meets the parameters defined by the WHO in the seminogram.
The semenogram is a basic test that is classically performed on male sperm, which consists of obtaining a sample of the sperm that is observed under the microscope, counting the total spermatozoa, motile sperm (progressive, slow and fast) and evaluating the spermatozoa's shape.
As we can see, this is a test that depends on the observer, variable (as men do not always have the same number of spermatozoa or motility at all times in their lives) and really old and not very technological.
To date, given that fertility research has focused mainly on the study of the female factor, as this is the factor that has led to the most rapid growth in knowledge, technique and technology in reproductive medicine, we have few tools for a more in-depth assessment of the male factor.
However, in recent years, research into the male factor has made great advances, such as the following:
- Sperm DNA fragmentation
- The action of external notes or defects in the packaging of the DNA transported by the spermatozoa can generate problems at this level, which, when fertilising an oocyte, will result in low-quality embryos or implantation failures.
- Sperm apoptosis
- Some sperm cells that are not suitable for fertilisation normally enter programmed cell death, apoptosis, also known as programmed cell suicide. These cells, which because they know they are not suitable for generating a good embryo have decided to die, are indistinguishable from normal cells and can therefore be used without the biologist being aware of it in assisted reproduction techniques, generating poor results.
- Alteration of sperm DNA protamination
- Protamins are proteins involved in the packaging of sperm DNA, which is necessary so that it is not altered during the long journey to the oocyte and the process of penetration of the oocyte. An alteration at this level will lead to poor results in assisted reproduction techniques.
- FISH in spermatozoa
- Although its use is currently somewhat controversial, it is possible to detect the presence of an abnormal number of spermatozoa with genetic alterations, which may be completely normal in their shape, motility and may have a normal semen count. These spermatozoa will never produce a healthy baby.
There are also many known cases of couples who have had sperm-attributable failures in which the sperm values of all tests performed were normal, but in which success was only achieved after sperm donation therapy (these are rare cases in which all known tests and therapies have been tried beforehand).
Alterations in all the parameters and tests mentioned above could explain male fertility problems that could occur with a normal semen analysis.
In addition, research in the field of male infertility is increasing and it is expected that in the coming years new concepts and knowledge will be developed, as well as other tests that have an impact on the study of semen, which has been little developed to date.
