Every year, Rob Michaels receives an email from an IVF clinic asking whether he still wants to store his frozen sperm. And every year, he confirms that yes, he does.
But he hasn’t told his wife. That’s because the couple, both 41, have agreed that they don’t want to have children.
However, like a growing number of men in the UK, Rob has chosen to freeze his sperm ‘just in case’.
Conscious that his chances of fathering a healthy child will decline with age, Rob told Good Health: ‘I want the option if my feelings change.
‘Being a realist I know a lot of marriages can end. And I have friends who suddenly wanted children in their late 40s and 50s.
‘Yet your quality of sperm rapidly degrades as you get older, meaning you might not be able to have children – and if you do, you’ve got a higher chance of having a child with birth abnormalities.
‘The idea of having a child with serious care needs who will be a teenager when I am in my mid-60s is unfair on all of us.’
Rob’s wife is unaware of his decision, which is why he’s telling his story under a pseudonym.
Beth Warren, a physiotherapist from Birmingham, went to the High Court in 2014 to fight to keep her dead husband’s sperm frozen so that she could have his children in the future if she chose to
Traditionally, it’s been young women, warned about their ticking biological clocks, who’ve taken steps to safeguard their chance of having a baby by freezing eggs for future use – some employers even offer it as a perk.
Now a growing band of young men are taking similar action – while Rob is giving himself a safety net against his marriage collapsing, others are freezing their sperm so that they can get on with their careers or wait for the right person to come along.
Private clinics report the number of young men undertaking this kind of ‘social freezing’ has risen by around 60 per cent between 2022 and 2024.
And some experts believe it’s to be encouraged. Dr Wael Saab, a fertility consultant and medical director at the Centre for Reproductive and Genetic Health in London, is unequivocal.
He says: ‘Men should strongly consider freezing their sperm while still in their prime.
‘For too long, the conversation around fertility and ageing was almost exclusively female.
‘The science is now firmly challenging that. A growing body of medical evidence has established that paternal age has a real and measurable impact on both sperm quality and fertility outcomes. The message is becoming harder to ignore: men should not wait.’
Certainly, science increasingly points that way.
The quality of a man’s sperm drops from as young as 40, according to study of around 3,000 men aged 16 to 56, reported in the journal Archives of Gynecology and Obstetrics in 2024.
Meanwhile, research published last year in Nature found that while around 2 per cent of sperm from men in their early-30s carried disease-causing mutations, this rises to 3 to 5 per cent among those over 43.
Researchers at the Wellcome Sanger Institute and King’s College London used new high-tech equipment to analyse sperm from 81 healthy men, aged between 24 and 75, with greater precision than ever before. And many of the mutations identified in the new study have been linked to severe neurodevelopmental disorders in children and an inherited cancer risk.
This echoes previous research that suggested children of fathers aged over 40 are more at risk of autism and childhood cancers – and the daughters of these men may be at a slightly increased risk of breast cancer.
Advanced paternal age is also linked to higher rates of congenital conditions, such as cleft lip or palate, regardless of the mother’s age.
Children of fathers aged 45 and older are more likely to be born prematurely and develop seizures than those born to fathers aged 25 to 34, according to a major study of 40 million births published in The BMJ in 2018.
There are implications for the mother’s health, too – with older fathers increasing a woman’s chance of developing diabetes during pregnancy, the same study found.
Faced with these worrying findings – and with the NHS only funding sperm freezing for specific circumstances (such as men about to have medical treatment such as chemotherapy, and for soldiers facing active service) – younger men are taking preventative steps.
‘We’re seeing more men in their 20s and 30s interested in freezing their sperm to preserve their fertility,’ says Dr Cesar Diaz Garcia, an NHS consultant in fertility medicine based in Scotland and chief medical officer at the private clinic IVIRMA Global.
‘While many men freeze their sperm because they have a health condition or are facing treatment for a condition that might affect their fertility, some freeze their sperm purely because they’re aware the quality of their sperm will deteriorate with age,’ he says.
He says this is part of a growing awareness of the potential implications of delaying fatherhood.
‘Although the impact of age is far less in men than in women from their 30s onwards, recent research has been clear that male sperm quality does decline with age – and, as a result, more men are becoming conscious of their own fertility and the steps they may need to take to preserve it if they want to start a family later in life,’ says Dr Diaz Garcia.
The High Court backed Ms Warren’s case to stop the sperm, taken before her husband started treatment for cancer, from being destroyed by April 2015
Private clinics report the number of young men who have decided to start ‘social freezing’ has risen by around 60 per cent
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‘Older paternal age can delay conception, increase the risk of miscarriage and even raise the chance of mental-health disorders in offspring,’ he adds.
(Some research suggests the offspring of older fathers may be more likely to develop bipolar disorder, for instance, but other factors may be involved.)
‘It can also affect IVF success, with live birth rates dropping significantly when the male is 40 or older,’ adds Dr Diaz Garcia.
Indeed, research co-authored by Dr Saab, published in the journal Acta Obstetricia et Gynecologica Scandinavica in 2021, found that only 42 per cent of men aged over 51 undergoing IVF had sperm meeting normal standards, compared to 61 per cent of younger men – and their partners were one-third less likely to achieve a live birth.
‘This was the case even when the woman was young and healthy,’ says Dr Saab.
Women are born with all the eggs they will ever have, and the number and quality declines steadily – with a sharp fall in fertility after the age of 35.
‘Men, by contrast, produce fresh sperm approximately every 74 days throughout their lives,’ says Dr Saab. ‘But quantity is not quality – and this is where men cannot afford to be complacent.’
As men age their sperm experience greater DNA fragmentation, where there are breaks in the genetic material.
‘Put simply: sperm is made in “factories” in the testicles and as you get older the testicles age with you,’ explains Dr Kevin McEleny, a consultant urologist at Newcastle Hospital NHS Trust.
‘These “factories” stop being so efficient as you age so you accumulate more DNA mutations.’
Apart from more traditional reasons for freezing sperm, such as before cancer treatment, Dr Saab says ‘pre-vasectomy banking is now increasingly common – where men are confident their family is complete but want a biological safety net, just in case circumstances change’.
But ‘social’ freezing – freezing sperm to delay starting a family – ‘is the fastest-growing group,’ he adds.
‘A man in his late-20s who isn’t ready for a family yet can bank his sperm at its peak biological quality, for use years down the line.’
Rob says that in his 20s and 30s, he was ‘on the fence’ about having children.
‘My friends began having children, but I generally found kids annoying,’ he says.
He and his wife married five years ago. Initially, he says: ‘We were both not keen on having children.
‘Then she found the hormones in the pill were making her unhappy. We talked and decided she should come off it and that if a baby happened, it happened.’
A year passed with no pregnancy. ‘By then we were both 38,’ says Rob. ‘Suddenly we went from “we don’t want kids” to “what if we can’t have kids?”.’
The couple went to a fertility clinic on the NHS and, as part of this process, Rob had to give several sperm samples for testing.
‘I had the option to freeze these in case we wanted IVF later,’ he recalls. ‘But as we went through more invasive tests, my wife decided she did not want kids after all. I was left with the dilemma – let the clinic destroy my samples, or keep them? I decided to keep them.’
Rob adds: ‘I’ve met older men who suddenly wanted children in their 50s after spending their life pursuing a career. There came a point where their work didn’t satisfy them any more, that they looked around and felt there must be more to life.’
Under UK law sperm can be frozen for a maximum of 55 years – although the man has to renew his consent every ten years.
And his consent is key: in a famous case in 2014, widow Beth Warren, a physiotherapist from Birmingham, went to the High Court to fight to keep her dead husband’s sperm frozen so that she could have his children in the future if she chose to.
‘Men should strongly consider freezing their sperm while still in their prime,’ says Dr Wael Saab
Her husband Warren Brewer had his sperm frozen before undergoing radiotherapy for cancer – the couple married six weeks before he died at the age of 32.
While he’d given his consent for her to use the sperm, the clinic where it was stored threatened to destroy the sample as he hadn’t renewed it. The court ruled in his widow’s favour.
There are financial considerations as well as practical ones, as every year sperm is stored, the bill adds up.
Private clinics typically charge between £400 and £600 to freeze the sperm and a yearly charge of £300 to £450 to store it.
And not everyone believes it is worth the money.
Dr McEleny, who is chair of the British Fertility Society, told Good Health: ‘We know that when men get into their 40s the quality of sperm declines a bit – and we know that the partners of older men take longer to conceive and are more likely to miscarry. There is also an increased risk of abnormalities such as autism.
‘What there isn’t is this abrupt cut-off in quality that women have,’ he adds.
‘So if I see older men I might mention that to them – but would it be worth freezing sperm on that basis? It’s difficult to say.
‘If they have good sperm quality at age 30 or 40, it probably wouldn’t be worth their while. It’s unlikely to have declined that much unless there’s some change in their health.’
But, he says, ‘men generally are not aware of the risks of delaying fatherhood.
‘Women are brought up to know how their bodies work. If a woman doesn’t have regular periods, she might be pregnant or assume she is infertile.
‘Men have no such markers. They don’t recognise the quality of sperm can decline or that there could be no sperm in their ejaculate.’
Dr McEleny adds: ‘What men can do if they’re concerned is to get a semen test. That might suggest earlier treatment, an earlier time to conceive or even storing sperm – but if it’s normal and they have good sperm at 30, or 40, it’s still likely to be reasonable by the time they get to 50.’
Rob, whose sperm is being stored for free on the NHS, says: ‘Freezing sperm when you are younger means they’re in better health, have better motility [their ability to efficiently move and fertilise an egg] and your genes are stronger and can make stronger, healthier kids.
‘I know my wife doesn’t want kids – and I’m fine with that, too. But I also know not all marriages last.’
