I don’t consider myself to be lucky. I have never won the lottery, or even found a fiver in an old coat pocket. But there is one aspect in life where fortune has smiled on me: I am eight months pregnant with my first child – the result of IVF treatment.

Around three-quarters of all IVF cycles fail. And results vary with age. Figures from the Human Fertilisation and Embryology Authority (HFEA) published in March state the average live birthrate for each fresh embryo transferred for women of all ages is 21%; for those aged under 35, it is 29% – the highest it has ever been. For older women, the picture is bleaker: 10% for women aged 40-42, for example.

In 2011, then aged 36, I underwent one cycle of IVF, funded by my local NHS trust, before I was treated for breast cancer. The embryos were frozen and in 2016 I embarked on the next stage: implantation. Funding was unavailable because I was by then over 40 and it was clear to me that IVF funding was unfair, with huge regional variations. Only 41% of treatment cycles are funded by the NHS.

The outcome amazes me still: the first implantation attempt was successful. But, now that the dust has settled, my experience in the private sector has left me feeling discombobulated and angry. According to a recent report by healthcare researcher LaingBuisson, the UK fertility market was worth £320m in 2016, with private investors increasingly interested in the sector. When I heard this, it struck a nerve. Surely infertile patients are the losers when healthcare is run to make profits for investors?

IVF is expensive. And what makes it worse, says Hugh Risebrow, the report’s author, is the lack of pricing transparency. “The headline prices quoted may be, say, £3,500, but you end up with a bill of £7,000,” he says. “This is because there are things not included that you need – and then things that are offered, but are not evidence-based.”

Those “things” are the add-ons – tests, drugs, equipment, procedures – offered on top of a cycle of IVF and charged for separately. And private fertility clinics sell patients add-ons that have no evidence behind them – in other words, they don’t work.

At the clinic I went to, add-ons included embryo glue, an adherent that may improve the chance of an embryo implanting in the womb, costing £330. I had declined appointments with the clinic’s nutritionist and acupuncturist (a recent study found acupuncture had no bearing on the outcome of IVF), and steadfastly ignored prominently displayed bottles of vitamins and supplements. When I was told by a member of staff not to bother with embryo glue, it didn’t even occur to me that this was a strange state of affairs. Anyway, I had my own add-on: a lucky dress. I wore it to my implantation and, given the outcome, I have worn it to all my scans since. There’s as much science behind it as some of the extras my clinic was touting and I can confidently say it has had a 100% success rate so far.

I still ended up with a bill well over £3,000. The price listed for frozen embryo transfer was £1,500. One cycle was cancelled before the implantation stage – costing me £775. Some extra charges were, as Risebrow notes, unavoidable, if not transparent, such as drugs – but some were avoidable. A thyroid function test was recommended – presented as necessary before treatment could begin – but I have since discovered the National Institute for Health and Care Excellence (Nice) recommends this should be offered only to women with symptoms of thyroid disease.

This is not unusual. Information about the efficacy of add-ons and extras is not presented in a clear and coherent manner by all clinics. Often, the treatments or technologies are new and evidence is not yet clear, or available. I am kicking myself that I didn’t question things more at the time – I have a master’s in science journalism. But once through the doors of the clinic, I just wanted to get pregnant.

Still, I got off lightly. Author and fertility campaigner Jessica Hepburn had 11 cycles of IVF – all unsuccessful – spending more than £70,000 over eight years. Hepburn says she “had everything going”, including controversial lymphocyte immunisation therapy, which involved being injected with her partner’s and a stranger’s white blood cells. “Patients do want add-ons – they will try anything because they are so desperate,” she says.

In 2016, add-ons were investigated by the BBC’s Panorama programme, based on research from the University of Oxford’s Centre for Evidence-Based Medicine. They found that 26 out of 27 add-ons were not supported by high-quality evidence. But has anything changed since then? Prof Carl Heneghan, the centre’s director, cites the HFEA’s traffic light scheme – something I heard about numerous times while researching this piece, but which not one person mentioned during the many months I spent having treatment. Launched in July 2017, the HFEA website lists the 10 most commonly offered supplementary treatments. They are graded as either green (more than one good quality study that shows the procedure is effective and safe); amber (a growing body of evidence shows promising results, but further research is still required) and red (no evidence to show it is effective and safe). None are green, six are amber and four are red.

Heneghan says it’s a step forward, but he wants to see more randomised controlled trials. “This is not a difficult area to reduce uncertainty … you want to know live birthrates, and you can do that systematically. But because this is the private sector there’s no incentive to reduce uncertainty.”

Heneghan has no truck with the argument that trials are difficult to do. This, he says, has “always been the answer.” “It’s almost like you’re dragging people into an evidence-based world. It’s 2018.”

Dr Jane Stewart is chair of the British Fertility Society, a body endeavouring to ensure patients are well educated. She is also an NHS consultant in reproductive medicine and gynaecology, heading up the Newcastle Fertility Centre. When I say the words “fertility market” to her, she sighs. What has happened, she says, is the “regrettable” practice of couples choosing treatments “like from a shop”.

“Straightforward IVF is a good treatment, it doesn’t need a whole lot of extra help,” she says. The answer, for those struggling with infertility, is simple: “People should have a consultation and have treatment that is good for them. It’s about taking the pressure off patients who feel that they need to buy everything.”

Prof Geeta Nargund is the clinical director of Create Fertility, a private clinic, as well as the lead consultant for reproductive medicine at St George’s, an NHS hospital in south London. “What’s important is that [add-ons] are evidence-based,” Nargund says. “We need regulation and legislation to ensure that [add-ons with no evidence] are not offered.”

I am slightly baffled, as I am looking at a price list from her private clinic, where add-ons include assisted hatching (red on the HFEA’s list), embryo glue, (amber) and endometrial receptivity array (ERA) for £1,200.

I point this out. “We positively discourage assisted hatching,” says Nargund. Embryo glue? “It’s a fantastic name, but it’s a joke.” ERA? “We have used it in the past, but now we have completely stopped.” So why list them, if she does not agree with their use? “Good question,” she says. For Nargund, it comes down to patient demand. If patients don’t see add-ons, they will go elsewhere, she says, and above all, she wants to educate patients.

I don’t doubt that Nargund is sincere. But it’s confusing. After all, if you see something for sale, don’t you assume that you could, and maybe should, buy it?

In these deep and muddy waters, it is the HFEA, the independent regulatory body for overseeing fertility treatment and research, that is best placed to bring clarity. But its remit does not extend to controlling or licensing much of what add-ons constitute. It has no control over drugs, for example, or reproductive immunology. However, its chief executive, Peter Thompson, is upbeat about changing the status quo. The traffic light system will be updated and expanded annually, and, in the autumn, the HFEA will require clinics to prove they are providing evidence-based information about add-ons to all patients. This will be enforced by HFEA inspectors, who inspect licensed clinics every two years. Not complying with guidelines, says Thompson, can ultimately result in loss of a licence. Why hasn’t work like this happened before? “This stuff takes time,” he says. “We [hope to] see an altogether more responsible attitude.” Until then, the advice for patients undergoing fertility treatment seems to be: question everything.