The male factor represents almost 50% of infertility problems. When we face several pathological spermiograms or despite having normal spermiograms no pregnancy is achieved, a complete andrological study is recommended.
How to read a spermiogram?
A spermiogram informs us about the number, mobility and morphology of the sperm.
In order to properly interpret the results of a spermiogram we need to apply the values for normality established by the WHO in 2009:
It exists a specific nomenclature for abnormal values:
- Hypospermia: volume beneath the normal level
- Azoospermia: absence of sperm in the ejaculate
- Cryptospermia: presence of very few sperm in the ejaculate
- Oligozoospermia : count inferior to 15 mio/ml
- Astenozoospermia: beneath normal motility level
- Teratozoospermia: sperm count of morphologically good spermatozoon beneath normality.
What is a Karyotype?
The Karyotype is determined via blood test and gives information about the amount and structure of chromosomes. A normal male Karyotype is 46XY.
The eggs as well as the sperm contain half of the chromosomes. An alteration of the Karyotype of a patient increases the risk of producing sperm with an abnormal genetic information. This would lead to the production of genetically problematic embryos resulting in non-ongoing pregnancies, sterility or abortos de repetición.
Therefore, it is recommendable to analyse the Karyotype before starting an assisted reproduction treatment like an In Vitro Fertilisation (IVF).
What can be done if the Karyotype is abnormal?
With an abnormal male Karyotype we dispose of two options: genetic analysis of the embryos via diagnóstico genético preimplantacional (DGP) before transferring them or using donor sperm.
What is meiosis?
Of the 46 chromosomes our cells have, 23 come from the father and 23 from the mother. An egg and a spermatozoon, in contrast to any other body cell, have half of the chromosome load. This way the embryo, as a result of the union of an egg with a spermatozoon, has 46 chromosomes. The process that reduces the number of the chromosomes to half is called meiosis. It only takes place during the production of eggs and the spermatozoa.
Occasionally, errors occur during the meiosis. These alterations imply a worse reproductive prognosis since it increases the amount of abnormal sperm, which does not mean that all of it is affected necessarily. An altered meiosis is generally associated with an abnormal spermiogram (especially with oligozoospermia) but can also exist in men with a normal spermiogram.
When is a study recommended?
The following factors make a genetic study of the sperm recommendable:
- Severe male factor
- Long term sterility without diagnosis
- Repeated failures with assisted reproduction techniques like the In Vitro Fertilisation (IVF) or egg donation
- Recurrent miscarriages after natural pregnancies which have not been proven other origin.
How to study meiosis problems?
Normally a spermatozoon has 23 chromosomes even though it might occur that they have one chromosome more or less or even carry the full set of 46 chromosomes of the original cell. The FISH study analyzes a certain number of spermatic chromosomes. A pathological outcome indicates that the percentage of abnormal sperm is superior to the normal population.
The great advantage of this test is that it is easy to carry out since it is done directly in the sperm sample.
The limitation of this technique is that only a certain number of the 23 chromosomes of the spermatozoon are studied which could lead to a normal result for a man with actual genetic abnormalities. For men with a low sperm count this technique might lead to no result at all due to the lack of material.
Through the testicular biopsy we can analyse the meiosis process directly. The intervention is simple and can be done ambulatory under local anesthesia. This way the division of the chromosomes can be studied throughout the different phases of the meiosis, which makes it much more specific and sensitive for the diagnosis of abnormalities than a FISH study. This is considered the definite test within the genetic study of the male factor.
What can be done if meiosis problems are detected?
Even though we can diagnose men with abnormalities of the meiosis, currently we do not dispose of the necessary means to identify the normal spermatozoa needed for assisted reproduction treatment like In Vitro Fertilisation (IVF). Since it is impossible to select the spermatozoon, the only viable option to improve pregnancy probabilities is a genetic selection of the embryo via preimplantation genetic diagnosis (PGD) or using a sperm donor. Using one option or the other depends on the results of the diagnostic tests as well as on the reproductive clinical history of the patients.
What is DNA fragmentation of the sperm?
The DNA of the sperm can be broken into little fragments. More fragments means worse reproductive prognosis. The DNA fragmentation of the sperm might be repaired in some cases by the egg. The better the egg quality the higher its reparation capacity. Hence, in treatments like egg donation where we dispose of many good quality eggs, the repercussion of an elevated DNA fragmentation of the sperm will be less important.
When is a sperm DNA fragmentation study recommended?
For the following cases a fragmentation study is recommended:
- Repeated failure of reproductive techniques
- Urogenital infections
- Male over 45 years
- Exposed to toxics or elevated temperatures
How is an elevated fragmentation treated?
We dispose of several techniques for the treatment of fragmentation:
- Eliminate the cause (treatment of fever, varicocele surgery…)
- Pharmacological treatment with antioxidants
- IMSI: permits to select sperm with less risk of fragmentation
- Obtain sperm directly from the testicle via TESA (testicular aspiration of the sperm under local anesthesia), which allows to use sperm which so far has not yet passed the epididymis where usually the DNA fragmentation takes place.
Microdeletion of the Y chromosome
The Y chromosome is only present in men and is involved in the production of sperm. Alterations in certain fragments of this chromosome are associated with sterility problems of male origin, especially in cases of azoospermia and oligozoospermia.
Mutation of the CFTR gene of cystic fibrosis
How does the mutation of the CFTR gene affect the fertility?
The mutations of the CFTR genes are associated with sterility problems and we find them related with cases of azoospermia and the absence of one and both sided spermatic duct.
What can be done if mutations of the CFTR gene exist?
As a genetic mutation it can be transmitted to the offspring, also passing on the problems these alterations cause. If on the other side the same mutation is handed on from the mother, the disease cystic fibrosis is triggered.
To avoid problems deriving from this mutation it is always recommended to study the couple carefully and carry out a preimplantation genetic diagnosis on the embryos during a cycle of In Vitro Fertilisation (IVF) in order to transfer healthy embryos.
What is varicocele?
A varicocele is a dilatation of the testicular veins. It might be associated with testicular discomfort but can also be absolutely free of symptoms. The varicocele is also related to an increased risk of DNA fragmentation.
How is varicocele diagnosed?
The diagnosis is made via physical exploration. A Doppler ultrasound of the testicle is a useful additional test since it detects an abnormal blood flow in the veins, which is associated with varicocele.
When does varicocele need to be treated?
In low level cases without symptoms, it is very controversial that its treatment improves fertility. In severe cases, surgery is recommended.