Fertility 24

Where did all the sperm go?

10 min read

Simon Körösi

Reviewed by: Joanna Elmes

Global alarm reports are continually being replaced about declining sperm concentration in men of all ages. no one understands why. What does it really take for fertility to stop being seen as a women's issue?


It is confirmed that fertility rates are below replacement levels in large parts of the western world. this means that fewer people are being born than the number who are dying. of course, the factors believed to affect this are many. lower infant mortality, economic stability, contraceptives, expensive childcare, and older mothers are just a few examples. but there is a cunning biological truth lurking around the corner. the truth that men's sperm concentration and quality has declined by over 50% in the last 50 years. a truth that has been given its own name - the male infertility crisis. and worst of all - no one knows why.


The research


Data from the globally noted meta-analysis from 2017 with almost 43,000 men, shows that this plunge is seen primarily in the western world, with no signs of slowing down. data from large parts of the middle east, africa, south america, and asia are limited, so a similar trend cannot be ruled out. this is especially true when china, the seat of the one-child policy, has shown the same clear fertility crisis. although the quality and concentration of sperm do not threaten the survival of humanity today, one of the co-authors suggests that the trend gives us until 2045 before half of all men lack functioning sperm.

as with much else in statistics and medicine, the curve will most likely eventually start to unfold. an important and interesting question is when this will happen. the most crucial question must, however, be why!? a few things that we know today worsen sperm quality are:

Pollutants in our waters


Plastic and chemicals from these (especially substances such as phthalates and bisphenol a)






Low/no physical activity

Poor diet

With this list, the conclusion is easy to draw that many men today carry bodies that are directly inhospitable for producing and storing sperm.


Health marker


Having decreasing levels of and quality in sperm tells not only the story of a fertility crisis, but also gives us an insight into the general health status of a man. diseases such as diabetes, cancer, and testosterone deficiency can manifest in poorer sperm, and with that, the state of sperm becomes a factor in assessing morbidity and mortality. so in addition to being crucial for the survival of humanity, sperm suddenly appears as a swiss army knife for men. but why then is there not global panic, like the one many experience for the environment?

a man's relationship with sperm is primal. sperm is a biological measure of masculinity, and follows the narrative of allowing the man to spread his genes and his name. while the man is considered capable of becoming a father in his 70s without a second thought, the pregnancy is considered geriatric (the study of diseases and care related to old age) when the woman is over 35 years old. moreover, there is a widespread societal norm today that the responsibility for contraception rests with the woman. condoms are either not reliable or enjoyable, and other contraceptives for men are not fast in production due to the side effects that arise in studies.

The female focus returns when fertility investigations in Sweden often examine the woman's fertility as a first step, but not always the man's. this is despite the fact that examination of the man's sperm would be cheaper and less invasive as a first step. one would like to believe that this is due to the overwhelming likelihood that the answer lies with the woman, right? the fact is, however, that it's evenly split. it is said that in 33% of cases it is solely due to the woman, 33% due to the man and in the remaining cases it is uncertain or a combination of both. just as women's eggs decrease in number from the day they start menstruating, the ability to produce new healthy sperm every 64th day decreases. the absence of healthy sperm is no joke. the risk of diseases such as down's syndrome, schizophrenia, autism, and leukaemia increases dramatically with the advancing age of the sperm-producing father. the fact is that the man's age is the single strongest factor for this risk. and just like in women, where fertility drops drastically after 35, the same applies to men.


Aside from age, the list of lifestyle factors plays a significant role; so significant that one might ask why the importance of nurturing these factors is rarely discussed in the male fertile population. smoking and alcohol should be completely abstained from before one wishes to conceive. the same applies to weight loss. a perhaps unusual but significant player here is heat. it's known that heat shortens the lifespan of sperm, decreases the motility of sperm, and in studies on insects, it has even been seen that offspring resulting from sperm exposed to heat will in turn live shorter lives. the advice here can sometimes sound like "avoid saunas" or "long hot baths," but the fact is that mobile phones in pockets, laptops on laps, and heated car seats might be even bigger culprits in this drama.

So, what should one do about this?


Ivf exists as a fantastic and relatively new solution for many who involuntarily suffer from childlessness. despite this, it is not a "one solution fits all" as it does not solve all causes of infertility. moreover, it is not a guarantee that successful pregnancy is achieved, and it is not a walk in the park to undergo ivf as it is physically and emotionally very challenging. did we forget to mention that there is also a hefty price tag that comes along for many?

sperm freezing is not yet mainstream, despite the clear effect of age on women's eggs also applying to men's sperm. with this argument, one can assert that more men should freeze their sperm. in a survey among young swiss military personnel, only 38% exhibited a sperm quality that meets who criteria. a notable figure. perhaps even more noteworthy is that only about 5.3% of the men asked chose to examine their sperm when given the chance. the reason for this was attributed to practical access to clinics, but also discomfort around the donation procedure, the awkwardness of the genital examination, and the feeling of not being mentally prepared to face a potentially negative result.

One can't just blame society. men, in general, neither like talking about their problems nor asking for help with them. of course, it's impossible to say what's the chicken or the egg here, but maybe the solution lies in tailoring communication and services specifically to men?
just as women can track their menstrual cycles, one could create a comprehensible sperm health monitor for men. a simple home test, connected to your other health data, has the potential to contribute to personal and preventative care. statistics on quality, concentration, and dna mutations could give us an increased understanding of each man's health status, and perhaps even explain if this is where the cause of the global sperm decline lies.

an overwhelming amount of studies show that there are several supplements one can take to give sperm concentration and sperm quality a boost. this is primarily believed to be because many men suffer from a partial deficiency due to not eating as varied a diet as they should, which can at least partially be compensated for with these supplements. some of these substances are selenium, vitamin e, coenzyme q10, n-acetylcysteine, and zinc.

There are solutions to male fertility that are scientifically in their infancy if the crisis should reach the edge of the precipice. intracytoplasmic sperm injection, gene therapy, sperm cell transplantation, or why not the science fiction-near method of getting a fully developed cell to backtrack in its development, to then become a targeted sperm or egg? maybe in the future, a same-sex couple will be able to produce a child?

no matter what the future holds, today, it still requires a sperm and an egg.
since men also constitute half of the issues around fertility, men should reasonably be included half as much in the discussions on fertility? the debate needs to be weighted differently and awareness needs to increase. companies could start offering sperm freezing as a benefit and fertility clinics could review guidelines and investigation focuses - something that could save both time and money for everyone involved.
it is up to each of us to bring this issue into the spotlight. and the potential is enormous! unlike eggs, which once damaged are damaged forever, it's never too late for the sperm. with targeted interventions and lifestyle changes, the trend can be reversed. behind healthier sperm health, you find a healthier male population and a longer life.
hopefully, it is a strong enough incentive for men to start examining their own soldiers and see what's actually going on beneath the surface.