At the Alternative Parenting Show last weekend, the London Women's Clinic launched the nation's first egg bank. The headline controversy is that, for the first time, following changes to the regulations, women can be paid for donation. Kamal Ahuja, its scientific and managing director, gave a solid account of how they arrived at the figure of £750. "The regulations clearly stipulate that the amount should not be so heavy that it destroys the basic spirit of altruism, but at the same time it should not be so low that it is meaningless to the donor who is giving so much time." And that, I think, is fair. However, there is a fight brewing around this industry, for years so celebrated that, in 2010, its white knight, Sir Robert Edwards, won the Nobel prize for medicine. He was responsible for the birth of Louise Brown, the world's first "test-tube" baby, in 1978. She was the first of five million. Who could see this as anything but a success story?

Well, it's a market, and a global market – like any other it will inevitably one day clash with human decency. The fact that it has taken so long is perhaps more surprising than the fact that it's happening at all. Susan Bewley, professor of complex obstetrics at King's College London, gave me a succinct example, from the case of lesbian-assisted conception. "They [the clinics] never tell them that fresh sperm is better than frozen because it works so much better. They always tell them, 'it could have an infection, we only use screened, perfect sperm'. These are nominal risks that you would take in any relationship – your husband might have an STI, or a chromosomal abnormality. The DIY is much more effective."

Bella and Lucy were at the Alternative Parenting show and went to the Women's Centre lecture. They had exactly this experience: they were told of the risks of using fresh sperm, and never told that it was much better at getting you pregnant. "What was much more eerie," Bella said, "was when she said, they wanted to make [choosing frozen sperm] more like a shopping experience, to make women feel more comfortable. So you can go on to the site, and say, 'I want this trait and that trait and this trait', and then you hit, 'add to cart'."

But more than any squeamishness around buying sperm like teabags, the problem is that this industry is over-claiming. Miriam Zoll is the American author of Cracked Open: Liberty, Fertility and the Pursuit of High-Tech Babies. She wrote an op-ed for the New York Times a fortnight ago, which concluded: "It's time to rein in the hype and take a more realistic look at the taboos and myths surrounding infertility and science's ability to 'cure' it." She elaborated (to me over the phone): "There's a formula in the way this is presented, culturally. Couple confronts problem conceiving; couple goes to clinic; couple is told their chances are low; couple remortgages and after 10 cycles, they have a baby.

"It's always this superhero patient who wins the jackpot. But if we look at the data from Europe, 77% of treatments fail. The Centre for Disease Control has it at 70% failure. But you never hear from the people who failed, which makes you think there's something wrong with you. The reality is that the science is fragile. It is amazing that five million babies have been born because of IVF but there must be at least 10-to-15 million couples whose treatments have failed."

A fight broke out in the mould (and on the scale) of Mommy Wars (stay-at-home v working mothers), with some frankly unsightly crowing from people who had successfully embarked on IVF ("As my two-year-old crawls into bed with me," one letter started, "I notice an article by Miriam Zoll …"). But the industry was stung too, with the president of the American Society for Reproductive Medicine writing: "While it sometimes takes more than one attempt, more than 60% of women who undergo treatments eventually end up with a baby." This figure is hotly disputed by Zoll. "It is unclear to me how they came up with that data," says Zoll, "because as consumers, we do not have access to who has had how many cycles in what clinic. If they have that information, they should certainly share it."

Bewley lifts the lid on a world of sleight of hand, massage and plain lying by omission in the world of fertility statistics. "It all depends on the denominator, the starting point. If you're counting everyone who walked into the clinic, or everyone who can afford one cycle, or everyone who can afford three cycles. If you're measuring people who have had three cycles, then they do have a 60% success rate, but the people who've been unable to afford more than one have a 30%. Some people who've dropped out, it will be because they're told they haven't got good eggs. So you're weeding the failures out of your success statistic, which turns it into a meaningless statistic."

I had an insight into their data devilment when I was asking Ahuja about success rates in egg donation. "We did a trial, and put through 45 donors who were suitable, to the counselling and other criteria, and they were matched either to a single recipient or two recipients. Every single donor has gone on to produce a pregnancy in either one of the recipients or both. It's very encouraging, 100%." But the donors aren't the ones to measure; it's the recipients who would chalk this up as a success or a failure. "65% of all the recipients became pregnant." Those are great odds, but they're not 100%, and – like an off-the-counter whisky – you have to know to ask.

Far more striking is Bewley's next point, related to the tendency of IVF to put in two embryos, which is itself partly a desire to boost the success data. "I was on the Nice fertility guidelines because I want good pregnancy outcomes and I'm very concerned about the measurement practices of the IVF industry. They don't compare themselves to natural births; they're just interested in live births. I've seen women on the labour ward have two babies at 25 weeks, both die, but they're counted as live births because they came out alive. They go into HFEA figures as live births … As a consultant on the obstetric ward, I remember seeing two women lose four babies on the same day." There are people in the IVF industry who no longer even see twins as a problem, just a buy-one-get-one-free scenario, but Bewley refutes this absolutely.

"As a junior doctor, I saw a woman die of IVF, and I wrote up the first maternal death in the literature. She had a twin pregnancy and she got very ill, and we thought it was pre-eclampsia and we induced her. Just before she delivered she collapsed; I thought she was having an eclamptic fit and had to deliver one baby after the other, and she was pouring with blood and her pupils were huge, so we knew something terrible had happened. I was talking to her on Saturday, we delivered on Sunday, and I went to her postmortem on Tuesday. And we predicted then that there would be an increase in older mothers, an increase in ovum donation and an increase in maternal death, with IVF. And that's what happened. So you can see that I come with biases. I come with a different set of experiences than the guys who've got pictures of babies all over their walls, and grateful patients paying them a lot of money."

There is a privatised-gains, nationalised-losses story here, too, of course – IVF treatment creates the pregnancy. Any complications to come out of that pregnancy are then devolved to the NHS. This isn't entirely the fault of the industry – there is something peculiarly difficult about understanding these figures. As Dr Fiona Kisby Littleton, an academic researching teenagers' understanding of fertility, points out: "They know the ovaries decline, but their worries around being a 40-year-old mother are all around, are they going to look good enough against the other parents, are they going to have wrinkles, are they going to be too tired, are they going to embarrass their four-year-old because they'll be the oldest mum in the playground? They never once say, 'hang on, I may not be able to get pregnant'. They don't connect the biological knowledge they just told you they had, with the socio-cultural expectation they have."

Kisby Littleton describes a fascinating interplay here between all the advances of medicine in the arena of female reproduction (scientific and political) – because abortion is framed in terms of choice, and because the pill allows us to not get pregnant, we think in terms of choice and control – if I can stop myself getting pregnant, I can stop stopping myself. If I can choose an abortion, I can choose a baby. Furthermore, Kisby Littleton and Bewley both intimate, but neither directly says, that the fearmongering around teenage pregnancy has made us believe we're all, as a species, a bit more fertile than we really are. "Your children are more likely to be infertile than have a teenage pregnancy. But you wouldn't know that from the discussions in society," says Bewley.

The void in all this, the void that Zoll's book has tried to fill, is where the voices of those couples whose fertility treatment didn't work should be. If they were louder, or present at all, in culture, and more to the point, prominent in clinics, things might look very different.

One woman told me anonymously about three rounds of egg donorship she had been through. "This treatment cost £8,000 for one shot, and they said I would have to wait two years. How do you think I felt? I was 39, I'd wanted to have a child for seven years. Just by sheer luck a different clinic was able to find me an egg sharer after six months. That failed outright. My sense of failure was so overwhelming. I felt it was my fault – women often do, it's classic. I was driven to the point of suicide. I'm not boasting or trying to impress anybody, but I really was. It's a horrible place to be.

"I decided to have another go. I got two teaching jobs, and I saved up another £8,000, and they got me a donor. She was 25, everything was brilliant according to the textbook, and I got a positive pregnancy test. And then eight days later I started to bleed. It was basically an early miscarriage. This kind of grief is very difficult to put into words, it's so deeply embedded that all you can do is focus on putting one foot in front of the other. To add insult to injury, we had frozen eggs left over. But they have a 20% chance of success overall. I just walked into that thinking, well, let's just get rid of these eggs. And I went for the pregnancy test, and they said it was negative. I thought, at least if I stay in public, I won't commit suicide, so I didn't get home all day. And there was a message saying, 'it turns out the pregnancy test has turned into a weak positive. It's unlikely to be viable, but keep taking the drugs and we'll scan again.

"So I had a scan, charting the death of this tiny little thing that was cleaving to my uterus. I could tell that this poor little thing had gone up two units when it should have quadrupled. I was witnessing the slow death of this tiny life. By this stage the nurses are terrified because they can see a person suffering this awful grief. You walk out of the clinic trying hard not to cry because you don't want to upset the women sitting there. I've never seen a woman walking out of the clinic in tears. Where's all that grief going? Because a lot of these women are getting terribly bad news.

"But I had to walk past the accounts office, and the woman was adamant about the 90 quid for the pregnancy test. I just thought, can't you give me a break? Could nobody have put their hand on my shoulder and said, 'I'm terribly sorry, this is an awful thing to be going through'."

This is Zoll's core message, that she underlines with determination and precision: "This is the human side that needs to be incorporated, and I believe that patients, when they go to a clinic, they need to have information, meetings with people who've failed as well as succeeded. They have cancer support groups, where they talk about the whole gamut. But infertility is shrouded in shame, and will only talk about success." Bewley refers to a study showing IVF to be as traumatic as chemotherapy, and makes a broader analogy. "It's a kind of death. We have our somatic deaths at the end of our lives, but we also have reproductive deaths."

"It's not a question of the industry selling false hope; but is the industry selling too much hope?" Miriam Zoll concludes.