Male infertility
The male factor (male sterility) is associated with more than 50% of cases of marital infertility, in 30% of cases it is solely responsible and in the remaining 20% it is combined with a female factor.
That is why at Institut Marquès we give great importance to men. In our Andrology unit we offer the best care for men to be able to analyze and detect any fertility problem that may hinder the path to fatherhood. To achieve this we have the latest study techniques on semen quality.
This is a field that has long been the subject of study for the Institut Marquès team, which has analyzed its possible causes and the factors that most affect male sperm quality.
Thanks to this experience at Institut Marquès we have at our disposal the best options to treat any anomaly detected in the andrological study. This analysis is advisable in all cases of marital infertility and, depending on the results obtained, it may be necessary to perform other studies or complementary tests to help us establish the etiological diagnosis.
Causes and antecedents
What are the main causes of male sterility?
The most frequent are due to alterations in the seminogram (decrease in the number and/or quality of spermatozoa) related to the deterioration of semen quality, although there may also be mechanical causes due to alterations in the genital tract that make it difficult or impossible to deposit the semen at the bottom of the vagina during coitus.
Deterioration of semen quality
The debate on the deterioration of human semen quality started more than 30 years ago. A study published in 1992 concluded that the average sperm concentration had decreased worldwide by almost 50% from 1940 to 1990 at a rate of 1% per year. Over the last 20 years, at least in industrialised countries, a decline in fertility has been observed. Beyond doubts about the role that the profound social changes experienced by industrialised societies may play in this decline, suspicions are spreading among the scientific community about the existence of a deterioration in semen quality.
Over the last decade, Institut Marqués has devoted a large part of its R&D efforts to the study of the male factor.
In 2002 we began to study the semen quality of Spanish men, first in Tarragona (study presented at the congress of the Spanish Fertility Society that same year), then in 2004 in Barcelona and La Coruña (study published in the journal Reproductive Biomedicine) and finally in 2008 throughout Spain (I National Study of Sperm in Young Men published in Andrology and carried out in collaboration with 62 reproduction centres). In 2011, together with the CSIC, we undertook a new study on the relationship between oligospermia or poor semen quality and the transmission of toxins during pregnancy, published in the journal Andrologia.
Our research and publications are demonstrating to the scientific community that the factors classically attributed to male infertility in terms of poor lifestyle habits are not the main cause of male infertility. According to our research, the key moment of affectation occurs during the fetal development of the testicle and is due to “estrogenic disruptors”, a long list of chemical substances that in the human body act as estrogens and that allow a woman to offer through the blood too high levels of estrogen to your male fetus during pregnancy. This explains the important variations in semen quality between countries and regions of the same country and makes us consider environmental contamination by chemical materials as the main cause of male sterility.
Mechanical causes of infertility
Abnormal location of the urinary meatus, either below its normal location (hypospadias) or above (epispadias), very pronounced penile curvature or very small penis size, and extreme obesity can hinder or prevent adequate deposition of semen at the bottom of the vagina during intercourse. Severe erection problems, very rapid or very delayed ejaculation and other ejaculatory disorders (ejaculation into the urinary bladder or ‘retrograde ejaculation’, more common in diabetics, or absence of ejaculation) can also prevent adequate deposition of semen in the vagina.
What medical history can affect fertility?
Among many others can affect fertility:
- Congenital malformations affecting the genitourinary area mainly undescended testes (cryptorchidism), agenesis of the vas deferens, incorrect outlet of the urinary meatus (hypospadias, epispadias).
- History of poor pubertal and sexual development (precocious puberty, delayed puberty).
- History of sexually transmitted diseases (STD) or prostatitis.
- Testicular trauma or torsion.
- Varicocele
- Exposure to toxic or hazardous substances at work, such as lead, cadmium, mercury, ethylene oxide, vinyl chloride, radioactivity and X-rays.
- Surgical interventions on the genital area (hernia, hydrocele).
- Medications
- Mumps after puberty
- Endocrinopathies
- Cystic fibrosis
Is heat harmful?
Intense heat can affect the quality of semen and its reproductive capacity, provided it occurs on a very continuous basis.
Several studies have shown that certain professions involving work at high temperatures can lead to a reduction in spermatozoa.
Fortunately, however, the body has its own self-regulating mechanism in the event of being exposed to a rise in temperature over a short period of time. This would explain the evolutionary theory of the male reproductive system.
In most mammals, the testes are located on the outside of the body, in a pouch called the scrotum. In humans, they remain inside the abdomen until about the last month of foetal life, when they begin their descent into the scrotal sac.
The genetic material is therefore exposed, rather than protected inside the body as is the case with the ovaries. This is thought to be because sperm production requires a temperature 2-4 degrees below body temperature.
In cold weather, the skin of the scrotum contracts and the testicle rises to come into contact with the body. In hot weather, on the other hand, the scrotum relaxes and the testicle descends away from the body to cool down.
In addition, the skin of the scrotum facilitates perspiration, as it lacks the subcutaneous fat layer.
A second mechanism for regulating the temperature of the testicle takes place in the spermatic cord, which among other structures contains the arteries and veins that respectively supply or drain blood to the testicle. It is here that a counter-current heat exchange takes place between the incoming arterial blood and the outgoing venous blood.
All these temperature regulation mechanisms therefore help to combat the effects of excess heat on semen quality.
Risky professions
Are there any professions at risk for male fertility?
There is an increased risk in certain professions where there is contact with physical substances or agents that are toxic to fertility. The list of work-related exposures responsible for reduced sperm quality includes: pesticides (farmers), radiation, heat (furnace workers, foundries, drivers), glycol ethers (shipyards and foundry workers).
Physical agents such as heat and radiation have been documented in case reports rather than in large-scale epidemiological studies, while little information is available on the effect of microwaves and electromagnetic fields in humans. Metals – especially lead and mercury – have been shown to be toxic to sperm in intoxicated or highly exposed workers.
Further research is needed before definitive conclusions can be drawn.
Do medications affect sperm?
Are there medications that negatively affect sperm quality?
There are multiple drugs that can affect fertility. It is essential when taking the patient’s medical history to ask about any medication he may have taken.
Among the most harmful drugs for reproductive function are chemotherapy drugs. It is important to know if the patient has undergone any chemotherapy treatment and its duration.
Other drugs that can affect fertility are: immunosuppressants, antidepressants, antiepileptics, antimetabolites, neuroleptics, hormones, some antibiotics.
Does the father’s age play a role?
Male age and infertility
The age of the father has an impact on fertility.
Men produce sperm throughout their lives. But the passage of time can lead to changes in the sperm count and oxidation of the spermatozoa and thus reduce the fertilising capacity of the sperm. In addition, damage to the genetic material contained in sperm increases with age and can cause disease in offspring.
The importance of the age of childbearing is well known in women and less so in men, but men also have their own biological clock.
The physiological ageing of the male reproductive system manifests itself in three ways:
– In the seminogram there is a very slow but progressive reduction in seminal volume (0.03 ml/year). This is due to the ageing of the seminal vesicles, which produce the fluid that carries the sperm produced in the testicle.
– The passage of time can oxidise and cause DNA chain damage in the spermatozoa.
– The appearance of mutations in the spermatozoa that can cause diseases in their offspring.
Male age and diseases in offspring
Spermatogonia, sperm precursor cells, multiply in foetal life and then stop until puberty, when they are reactivated again.
During the period of active sexual life, the multiplication rate is approximately 23 per year. Thus, for example, the spermatozoa of a 38-year-old male have a history of about 540 divisions and of a 50-year-old male about 800.
We know that in the cell multiplication phases there is a risk of mutations, i.e. that an external pathogen induces errors in the DNA. This risk is greater the more divisions that have taken place, in direct relation to the age of the male.
Paternal age over 50 years is related to the following pathologies in offspring:
Diseases such as achondroplastic dwarfism, new cases of neurofibromatosis, tuberous sclerosis, Marfan , Apert syndrome, aniridia and bilateral retinoblastoma.
Other pathologies such as schizophrenia, bipolar disorder and autism. Late parenthood increases the risk of having a child with autism spectrum disorder: Every 5 years that the parents turn 5 increases the chances of having a child with autism spectrum disorder by 18%.
What are genetic mutations?
Mutation is a change in the information carried by a gene. People have 23 pairs of chromosomes and each chromosome contains a certain number of genes. Each gene is responsible for a characteristic of how a human organism looks or functions. For example, one gene determines the colour of the skin, another the length of hair on each part of the body, and so on.
Genetic mutations are necessary changes for the evolution of the species and for adapting to the environment. For example, dark skin colour in very hot environments.
But there are also nature’s mistakes: abnormal mutations can occur in a group of cells and give rise to a tumour, or mutations in reproductive cells and give rise to the birth of children with hereditary diseases.
For example, in achondroplastic dwarfism, the mutation affects a gene responsible for growth. It can be inherited, as 50% of the children of an affected person will be affected, but it can also be a ‘de novo’ mutation and a child can be born with dwarfism without having any previous history.
More than 50% of sterility cases are due to the male factor. Institut Marqués is one of the few centres with an Andrology department to diagnose and treat male fertility problems.
Treatments
Can IVF be performed when the semen is severely altered?
We know that 18 percent of patients with severe sperm alternation have genetic abnormalities in the sperm that will prevent successful IVF treatment. In other cases, most pregnancies will end in miscarriage or foetal malformations. For this reason, our team always advises a prior genetic study of the male, as it seems to us to be too high a percentage.
Are chromosomal alterations detected by means of meiosis or FISH studies treatable?
Chromosomal alterations have no treatment. However, we know that males who suffer from them can produce a minimum percentage of chromosomally normal spermatozoa, and although there is currently no technique that allows us to separate chromosomally normal spermatozoa from those that are not, before using them in IVF techniques, we can analyse the chromosomes of the embryos obtained in IVF before transferring them to the uterus through Preimplantational Diagnosis (PGD) and thus be able to select healthy embryos that evolve to achieve the desired pregnancy.
Is sperm DNA fragmentation treatable?
Given that in the vast majority of cases, sperm DNA fragmentation occurs at the epididymal level, and that the mechanisms of fragmentation include both oxidative damage produced by free radicals and enzymatic hydrolysis induced by caspases and endonucleases, the treatment recommended today is the use of testicular spermatozoa obtained by the testicular aspiration technique or TESA, in combination with sperm microinjection or ICSI. While medical treatment with antioxidants could prevent, at least in part, oxidative damage induced by free radicals in the epididymis, there is no treatment to prevent damage caused by caspases and endonucleases. Recent studies at our Centre confirm the efficacy of TESA-ICSI treatment in patients with an increased degree of DNA fragmentation in semen and also the efficacy of IMSI.
