The indicators that Spain is heading to be a subfertile country according to the parameters of the WHO follow one another. A work published at the end of last year with studies from more than fifty countries comparing sperm records between 1973 and 2018 of healthy men pointed out that semen quality had been reduced by half in that period. And the reports from assisted reproduction clinics point in the same direction.
A study by the IVI group on samples of 120,000 patients from the last two decades concludes that the risk of men requiring fertility treatment to become fathers has grown by 9%. And the analysis of the 5,000 samples examined in the last 5 years by the Bernabeu Institute (IB) confirms a 16% decrease in sperm concentration and 12% in their motility.
And the worst quality of semen is not detected only in the case of men who come with their partners due to fertility problems. It is also appreciated among sperm donor candidates, who are healthy young people between 18 and 35 years of age who are presumed healthy. The Bernabeu Institute reported a few days ago that, in 5 years, the donor acceptance rate for its sperm bank has gone from 15% to 8%. And eight out of ten rejected were due to low semen quality.
The acceptance rate provided by other semen banks consulted is somewhat higher -10% explained by IVI Valencia or 20% by Fundació Puigvert- but they all say that the main reason for rejection is that the candidate’s semen does not comply with the required quality standards.
Of course, the seminal quality parameters requested from donors are more demanding than those set by the WHO to consider a man subfertile. “They are asked, for example, between three and four times the amount of sperm per milliliter that is considered normal because the samples are going to be frozen and thawed, and in this process there is a loss of seminal quality,” explains Gabi Adalid. , Andrology nurse and coordinator of the Fundació Puigvert sperm donation programme.
All in all, the scientific director of the IB genetics laboratory, Belén Lledó, assures that 40% of donor candidates who are rejected due to poor semen quality “do not meet the WHO criteria, are subfertile and are advised to go to the urologist”.
What is the cause of this drop in semen quality? “It is difficult to attribute the problem we have with fertility to a specific cause, because many factors influence it and are interrelated,” replies the president of the Spanish Fertility Society, Juan José Espinós.
Lluís Bassas, andrologist and director of the Fundació Puigvert sperm bank, assures that this negative vision of the evolution of semen quality is influenced by methodological changes when analyzing it, as well as advances in genetics that cause more candidates to be rejected. going through the delay of the age at which people are encouraged to be fathers or mothers.
But, as Rocío Rivera, director of the IVI Valencia andrology laboratory, explains, what they see in the samples from young donors indicates that it is not only a matter of age but rather of lifestyle.
“What has changed the most in recent years is the way we live: a more sedentary life, more exposure to pollutants, a more unbalanced diet, more obesity, more consumption of toxins, more stress… and all of this conditions not only to the person in question but also to their descendants due to epigenetics”, sums up Dr. Espinós.
And among all these changes, fertility experts are clear about one that is clearly affecting the semen of many men: the cult of the body. “The gym effect is reaching fertility consultations; The substances that many men take to improve their sports performance destabilize the hormonal system and this affects the formation of gametes, semen quality and fertility”, Lledó summarizes.
“Anabolics are extremely detrimental to male fertility and their effect is immediate; and there are many men who consume them, who take steroids to stimulate their strength, improve their resistance to exercise and their physical appearance; We see it in the consultation, because the drop in sperm that these substances produce is very exaggerated, but many deny taking them because they are embarrassed, because they have become addicted, or because they don’t even know what the gel they put on their skin contains because It was recommended to him by someone at the gym”, emphasizes Dr. Bassas.
An experience similar to the one recounted by the president of the SEF: “It is very common: muscular patients who know that it is impossible for their infertility to be due to another cause and they deny that they are taking anything… The problem is that they are products that are beyond control from the health authorities, which are sold as something positive to be more handsome, have more muscles… and nobody explains to these kids that it can have a negative effect on sperm production”.
But anabolic drugs are not the only way in which the cult of the body weighs down the quality of the semen. “Treatments for baldness and hair implants have become popular and the drug that is taken, finasteride, increases testosterone levels in the body and this deregulates the hormones that cause sperm to be generated,” explains Dr. Rivera, from IVI Valencia.
Of course, both in the case of anabolic drugs and hair treatments, the effects on sperm are temporary. “When you stop taking it, the hormones return to their levels and you regain fertility, but sometimes it takes months,” Bassas points out.
Stress is another lifestyle factor that is weighing down the quality of semen in many men. “We notice it a lot in the donors; young men who are accepted into the program because they have high semen quality and suddenly, in one of the subsequent samples, the sperm concentration has plummeted; and you talk to them and they explain to you that they are taking exams or going through a time of great stress at work”, explains the director of the IVI Valencia andrology laboratory, Rocío Rivera.
And he explains that they also detect changes in the seminogram (the study of semen samples) when the young man has gone out to a party or has slept little, which confirms the impact that habits and lifestyle or the consumption of toxins have on the quality of the sperm.
Another determining factor in the decline in male fertility is, according to the specialists consulted, exposure to chemical pollutants from the mother’s womb.
Nicolás Olea, a doctor, researcher and professor at the UGR and one of the leading experts in endocrine disruptors, assures that “exposure to high temperatures and atmospheric pollution have a significant impact on fertility and sperm quality” because the organs Male reproductives “are especially susceptible to exposure to environmental chemicals.”
From the University of Panama, where he currently works as a visiting professor, Olea explains to La Vanguardia that “it has been documented that environmental contamination unfavorably affects semen quality by impairing the process of spermatogenesis and steroidogenesis, and affects the functionality of Sertoli cells and sperm functions, leading to decreased fertility.
She adds that there are also studies that have shown an association between maternal exposure to endocrine disruptors such as pesticides, bisphenols, phthalates and heavy metals during pregnancy and a low volume of ejaculated semen and sperm count in children.
“It is suspected that xenoestrogens, endocrine disruptors, could be influencing infertility but also in the increase in cases of cryptorchidism (a poor descent of the testicles) and testicular cancer that we see, but it is difficult to have evidence on their effects because you cannot completely isolate the person from environmental contaminants in order to have a control group with which to compare”, comments the andrologist Lluís Bassas.
Olea admits that there is little data on the real effect of chemicals on male fertility because the studies have been done with people from environments where pesticides or other substances are in very high concentrations and not in the general population.
However, he believes that although more research is lacking, there are indications that it is necessary “to inform pregnant women about the potential dangers of chemical substances that during pregnancy can harm the fertility of their children.” And she believes it pays to reduce air and chemical pollution, heat exposure and introduce some positive lifestyle changes to prevent adverse effects on semen quality.
