“My body and my inability to lose weight failed me in the one thing I ever really wanted,” says Carolyn Nicholls, 47, from Nottingham.

“I’ve yet to forgive myself for that.”

In 2011, after a year of trying to conceive and one miscarriage, Carolyn and her partner visited their GP for help. She was weighed and informed she was 4lbs over the BMI limit that had been set for accessing fertility treatment in her area.

Carolyn, who says she was “getting at least the recommended amount of exercise and eating a healthy diet”, spent months trying to lose the weight, without luck. The couple eventually paid for three cycles of IVF at a private clinic, which cost around £8,000 per cycle. Sadly, each cycle failed.  

“We have now had to accept that we won’t have children,” says Carolyn. That was 10 years ago, but the NHS is still turning away couples on the basis of their BMI today, despite an ongoing debate over whether it is an accurate indicator of health. 

BMI, or body mass index, is your weight (in kilograms) divided by the square of your height (in metres). An ideal BMI is in the 18.5 to 24.9 range for most adults, according to the NHS.

However, even the NHS acknowledges that it “is not the perfect measure of your overall health,” noting that BMI “can’t tell if you’re carrying too much fat or you’ve got a lot of muscle.”

In a recent House of Lords debate on BMI, former Olympic silver medallist Sir Colin Moynihan pointed out that many Olympic athletes would be considered above the “healthy” BMI measure. Meanwhile, some patients have been denied access to eating disorder services if their BMI is not considered “low enough”.

Daniel Davies, 36, from Bedford, and his wife Sarah, 32, are about to start private fertility treatment, after being turned away by the NHS in 2020.

Sarah has polycystic ovary syndrome (PCOS) and in 2018, following two miscarriages, she was diagnosed with Hashimoto’s disease – an autoimmune disorder that attacks your thyroid and can impact pregnancy.

She’s since had a third miscarriage. Despite these significant barriers to natural conception, the couple have been denied IVF treatment on the NHS – because of Daniel’s BMI.

“The irony was, I didn’t have any issues as far as we knew from semen tests and blood tests, so it didn’t seem fair at all,” he says. “I felt victimised by it.”

The National Institute for Health and Care Excellence (NICE), which provides evidence-based guidance for health and social care, does not recommend blanket BMI limits for either male or female patients when it comes to accessing fertility treatment. 

However, it does suggest patients should “ideally be in the range 19–30 kg/m2 before commencing assisted reproduction” and some clinical commissioning groups (CCGs), which control the funding of IVF at local level, have used this as an excuse to impose their own restrictions. 

Couples are subject to a postcode lottery: while some CCGs list no BMI requirements, others vary, with restrictions set at 35 kg/m2, 30 kg/m2 and 29kg/m2 in different parts of England. Private clinics rarely impose the same limits. IVF is expensive and BMI is just one way CCGs are restricting access to treatment on the NHS to reduce costs and, they claim, maximise success.

Some local areas use age, with women as young as 35 being told they’re “too old” for treatment. In other areas, IVF is restricted if you already have one child, or if your partner has a child from a previous relationship. In a handful of areas, free IVF has been cancelled for almost everyone but cancer patients, under extreme cost-cutting measures. 

Daniel and Sarah are only able to afford private treatment because they launched a GoFundMe fundraiser, asking friends and family for help.

As a 6ft2in ice hockey player, Daniel says he’s “definitely a bigger guy”, but that he is not at all unfit. Being told to lose weight by the NHS, without sufficient support, had a serious impact on his mental health, he adds. “I think it’s safe to say that my relationship with food is now terrible,” he says. “I have a borderline eating disorder and feel guilty every time I eat anything, often eating very little and then smashing a load of calories at once making myself sick.”

Daniel was initially completely against the idea of crowdfunding for treatment, saying: “It felt like begging, at a time where most people were really struggling.”

Eventually, his desire to be a dad and Sarah’s persuasion won over, and he’s now glad they’re seeing a private consultant. Being turned away for NHS treatment has made a difficult fertility journey even harder though. “There was definitely a strain on our relationship afterwards, throughout, and still now,” says Daniel. “We’re working on it, we have ongoing therapy to help us work through this entire thing. I think the whole process has made us a lot more anxious.”

Like Daniel, Alice, 42, from London, says her experience with NHS fertility services has altered her relationship with food. In 2011, when she accessed her first round of IVF, her BMI was around 28kg/m2, but she put on weight during treatment. 

“I don’t know if it was the stress or hormones or what, but at the end of that cycle, which wasn’t successful, my BMI was just above 30,” says Alice, who chose not to share her surname.

At her follow-up appointment, her doctor informed her she no longer met the BMI criteria for NHS-funded IVF. She was advised to lose half a stone and come back for another appointment in six weeks time if she wanted to try again. 

“To achieve that, my normal, healthy, balanced diet and exercise habits went out of the window and I started taking a fat blocker and went on a really extreme diet to try and meet that threshold,” she says. “The whole time I was doing it, I was thinking: ‘This can’t be the best preparation for a healthy pregnancy.’”

Alice and her husband had a daughter from that round of IVF. A few years later, when they wanted to give her a sibling, they had to go to a private clinic: in their area, as she puts it, “you only get one free baby”.

At the private appointments, Alice’s weight was never raised. “If you’re paying, apparently BMI doesn’t matter,” she says. “I was 10kg heavier probably when I had my son, and nobody said ‘you’re too fat’.”

That all three couples who spoke to HuffPost UK found private clinics willing to offer them treatment poses questions about the medical basis of the NHS limits.

So why does BMI continue to be treated as a factor in IVF access? 

“The use of BMI as a shorthand for overall health has always been controversial and the debate is ongoing – just this month a Parliamentary Committee urged Public Health England to scrap it in favour of a more health-focused approach,” explains Dr Marta Jansa Perez, director of embryology at the British Pregnancy Advisory Service (BPAS).

“Certainly you can only tell a very limited amount about somebody’s health from their BMI in isolation: overall health depends on so many other things.”

Dr Perez says there is some evidence that patients with higher BMI may have a lower chance of success conceiving, as well as higher risks from fertility treatment. Obesity – which can be identified by BMI in some instances – is associated with lower fertilisation rates, poor quality embryos and higher miscarriage rates, the NHS says. 

“There will be some patients for whom treatment is not safe at their current weight (whether that’s too low or too high),” says Dr Perez. “So BMI needs to be considered when deciding whether to proceed with treatment, but it’s not the only factor.” 

But instead of blanket BMI limits, Dr Perez believes suitability for fertility treatment should be considered by medical professionals on a “case-by-case basis, making decisions in the best interests of the patients in front of you.”

After hearing these three couples’ stories, she agrees that more support – both practical and emotional – should be given to those who are told their BMI is too high. “Any policy that promotes crash dieting to get the BMI down below a certain magic number – regardless of the other negative health consequences – should be re-examined,” she says. 

“Every patient deserves the chance to have a supportive, respectful conversation with their health professional about their readiness for treatment. If during this conversation it is agreed that they do need to reduce their weight, they should be supported to do so in a way that’s healthy.”

HuffPost UK contacted the Department of Health and Social Care about the variation in BMI requirements faced by those wishing to access NHS IVF. We also asked for comment regarding mental health support in relation to BMI.

“Patients should have fair and equal access to NHS infertility treatment when they need it, no matter where they live. Decisions on IVF treatment are rightly made by doctors, based on a patient’s individual clinical needs, in line with NICE guidelines,” a spokesperson said.

They added: “We are committed to creating a health and care system that works for all women and we urge all women to come forward and share their experiences in our call for evidence so we can create the first government-led Women’s Health Strategy that will improve the health and wellbeing of all women across England.”

Without a change to the system, patients like Carolyn will continue to suffer.

A decade on, as well as managing the grief of not being a parent, she’s still struggling with low body image after being denied NHS IVF. 

“My mental health took a real bashing, as I felt that we had failed to have children because of my weight,” she says. “I hate how I look and am always conscious of my shape and how my body moves and works because of my weight.

“At the end of my weekly yoga class, my teacher offers the promise ‘I love and honour my body’ – I just can’t join in.”