Soaring infertility, forcing couples to rely on arduous, expensive medical procedures in order to have children. Birth rates plummeting across the world. Governments issuing dire warnings over the future of the human race.
It seems the stuff of dystopian novels, but some experts say this bleak future may not be far off.
A growing body of research has shown that sperm counts – a measure of male fertility – are declining globally, with some estimates showing a fall of as much as 60 per cent in little over a generation.
And it’s only getting worse. Before the year 2000, studies showed the average sperm count falling by roughly one per cent each year – since then, the rate of decline has doubled.
In fact, according to the UK’s most recent Fertility Index Survey, young men today are nearly three times more likely to have fertility issues than older generations.
And it’s being reflected in our birth rates. Britain has now fallen below its fertility replacement rate – meaning not enough babies are being born to maintain the population.
Worryingly, by as soon as 2045 by one estimate, the average male sperm count will be approaching zero.
The consequence, says Professor Shanna Swan, one of the leading experts tracking the trend, could be that the majority of British couples are soon forced to rely on assisted reproduction.
Research claims that over-the-counter painkiller paracetamol could be wreaking havoc on men’s reproductive systems
Now some say they have identified the factors fuelling the alarming decline. And one of them could be a pill that millions of us take every day.
Research claims that over-the-counter painkiller paracetamol could be wreaking havoc on men’s reproductive systems.
Chemicals in everyday items such as till receipts, milk cartons and moisturisers could also be having a damaging effect.
Known as endocrine disruptors, they can mimic and replace hormones – throwing our reproductive systems into disarray.
These are controversial views that some say lack sufficient scientific evidence. But perhaps more surprisingly, some of the experts pointing the finger at these man-made toxins now believe their impact can also be reversed.
Professor Swan, an environmental and reproductive epidemiologist, was one of the first to raise the alarm around plummeting sperm counts. Now she’s convinced it can also be treated within your own home.
In fact, she’s in the process of running a first-of-its-kind study on the topic – looking at couples struggling to get pregnant and guiding them through the process of changing their lifestyle.
From swapping scented lotions to unscented alternatives, cutting out processed foods and removing plastics from their kitchens, these are easy changes to make.
Professor Swan, an environmental and reproductive epidemiologist, was one of the first to raise the alarm around plummeting sperm counts
And while the results of the trial are still under wraps, Professor Swan says it makes one thing clear: there are tangible ways to avoid sperm-killing chemicals.
‘It takes paying attention and the will to do it, but we can lower our exposure,’ she tells The Mail on Sunday. ‘There are things we can do in our homes that can increase our chances of having a baby. And many, many people are willing to make these changes.’
Unlike women, who are born with all the eggs they will ever have, men begin to produce sperm between the ages of ten and 12 and continue to do so for the rest of their lives.
The average man will make millions of sperm cells every day, that then take about three months to fully mature.
Once fully formed, sperm is mixed with seminal fluid – a whitish liquid produced by the prostate gland – to form semen. But despite being able to survive outside the body, sperm cells are surprisingly fragile.
Seemingly small changes in body chemistry can have a profound impact on their ability to move, grow and fertilise an egg. And any shift in the amount of sperm in a given quantity of semen – the sperm count – can impact a man’s ability to conceive a child.
Scientists track changes in sperm counts by collecting samples from thousands of men and calculating an average.
According to researchers from the Hebrew University of Jerusalem, who analysed data from more than 42,000 men from across North America, Europe, Australia and New Zealand, sperm counts fell by an average of 1.2 per cent per year from 1973 to 2018 – dropping from 104 million sperm per millilitre (million/ml) of semen to just 49 million/ml. At 40 million/ml, explains lead researcher Professor Hagai Levine, you start to see real fertility problems.
Professor Swan says: ‘There are things we can do in our homes that can increase our chances of having a baby. And many, many people are willing to make these changes’
And to make matters worse, the drop in sperm count is now increasing each year, with an annual 2.6 per cent reduction since 2000.
Many point out that toxins in our environment have increased at the same time that male fertility rates have declined.
‘We know it’s not genetics because genetic changes take a long time to have an effect, and what we’re seeing has occurred over mere decades,’ says consultant urologist Dr Jonathan Ramsay. ‘So it must be something in the environment.’
Increasing obesity rates and sedentary lifestyles in the latter half of the 20th century have long been cited as a cause of declining birth rates. Obesity levels in Britain doubled from 1993 to 2022 – 64 per cent of the population are now either overweight or obese.
Excess fat affects fertility by causing hormonal imbalances, menstrual irregularities and reduced sperm quality – making it much harder to conceive and increasing pregnancy risks.
But a growing number of experts claim other factors are at play – including exposure to the most commonly taken medicines.
One of the pills linked to declining sperm counts is paracetamol. While it’s still unknown exactly how it changes sperm quality, some believe it does so by reducing production of nitric oxide – the substance responsible for regulating sperm movement – as well as the ability to process testosterone.
Researchers from Brunel University in London examined levels of paracetamol in the urine of nearly 1,000 adult men in Denmark and found every one had levels higher than was considered safe. They concluded that, in combination with other endocrine-disrupting chemicals, high doses of paracetamol can build up in the body, creating a near-constant toxic exposure that depletes male sperm count.
But it’s pregnant women who should be the most cautious with the drug, say other experts.
Lab experiments have shown that paracetamol given to mice grafted with foetal testicle tissue can reduce the production of testosterone in male foetuses, making it harder for them to produce sperm in adulthood.
Unlike exposure in adulthood – which can usually be reversed by removing the chemical and allowing three months for new sperm to develop – exposure in the womb tends to be permanent.
In light of this, Dr Rod Mitchell, professor of paediatric endocrinology at the University of Edinburgh, strongly feels women in their first trimester should not take the drug – or, if it’s medically necessary, to take the lowest dose for the shortest possible time.
He says: ‘The first trimester is a critical period in foetal development where you need enough testosterone to be circulating in the foetus to program its future reproductive health.
‘Any reduction in the hormone during this period could give that baby problems with fertility – as well as an increased risk of testicular cancer – in adulthood.’
But, as a clinician, Dr Mitchell is also wary of scaring women off the drug. ‘Fever and pain are also not necessarily good for mother and baby,’ he adds.
Ibuprofen has also been linked to a reduced sperm count. As with paracetamol, some researchers believe the drug can impact sperm production by lowering testosterone levels.
Endocrinologist Professor Annice Mukherjee said: ‘The effect of endocrine disruptors is an issue all good endocrinologists are genuinely concerned about. Not everyone’s fertility will be affected equally – genetics and other lifestyle factors will play a role.
The average man will make millions of sperm cells every day, that then take about three months to fully mature
‘Cause and effect is very hard to prove, as there is so much at play. But all the research we have suggests these chemicals, are a risk to fertility. I’m worried for my own children.’
But not all experts are as convinced, however.
Male health expert Professor Allan Pacey, based at the University of Manchester, is sceptical of the claim that environmental factors are behind the falling birthrate. Instead, he believes it is due to people having children later in life.
‘The single thing you can do if you want to be fertile is have a baby when you’re young,’ he says. ‘A century ago, the average father was in his late teens, early 20s. Now he’s in his late 30s. Older men not only produce fewer sperm but the sperm they do produce is less healthy.’
But Professor Swan says people simply choosing to have children later cannot explain why animals are seeing a decline in fertility. She says: ‘They’re not subjected to pressure to join the workforce or use contraception or delay their childbearing.
But they are subject to the same chemicals in the environment we are – and this is one of the reasons why I am convinced environmental chemicals are playing a major role in declines in reproductive function.’
Prof Swan also argues that, if her theories hold, the damage could be reversible. And that’s what she is setting out to prove in her study, tracking couples who are struggling to conceive.
The results will be published in the next few months. However Professor Swan says changes like the ones the couples made – swapping their personal care products and home items for plastic- and chemical-free versions – do work.
‘I’ve worked on studies that have taken five to ten years to complete, and cost five to $10 million to do, and I published them and spoke about them at conferences, and it didn’t change anything,’ she says. ‘So now I’m doing quicker studies that will get
people’s attention. And this is the first. We want to show people that there are things they can do in their life to increase their chances of having a baby.’
‘I’d give anything to be a dad’
Postal workers Ryan and Megan Lamour are about to begin their third round of treatment, which they hope will be successful
Megan and Ryan Lamour, 27 and 28, knew they were each other’s ‘one’ from the moment they first met, aged just 16.
After moving in together in 2020, the postal workers, pictured, from Northern Ireland, decided to take the next step and try for a baby.
But after two years with no luck, they realised something was up. It was during the pandemic, so they ordered an at-home fertility test for Ryan – which came back inconclusive.
Confused, the couple booked an appointment with their GP, who sent them for further testing.
But while Megan’s came back normal, Ryan received some devastating news – his sperm count was so low that their chance of conceiving naturally was just 0.5 per cent.
‘It was tough,’ Ryan says. ‘I feel more guilt than anything else, because the issue’s on my side.
‘All I want to do is be able to give Megan the gift of being a mother – and I can’t do it as easily as other people can. It’s taken a while to come to terms with that.’
The couple say they have no explanation as to why Ryan’s sperm count is so low – he’s not a heavy drinker or smoker, and eats healthily.
But after cutting out alcohol, Ryan’s sperm count has improved enough to start IVF. The couple are about to begin their third round of treatment, which they hope will be successful.
‘I can’t put into words how much it would mean to have this baby,’ Ryan says. ‘I’d give anything to be a dad.’
