They are the frozen ones. There are 117,619 of them in this country, enough to populate Blackburn or Cambridge, but they cannot walk or talk, eat or even breathe. They are the almost-people - living balls of human cells suspended in liquid nitrogen at sub-zero temperatures, waiting for their lives to begin again.
Lois Walker was one of them. She was conceived in October 1997, but not born until April 2000. Instead of nine months, her gestation period lasted more than two years. Lois is now five years old. "We sometimes say, 'You should be seven now,'" says her mother, Laura Walker. "We laugh about it. But when you stop to think, it is pretty spooky."
The eight-celled embryo that would become Lois spent those 30 months in a plastic tube, stored in a metal flask in a fertility clinic. Was she alive? Did she have any human rights? What should have happened to her if her parents had split up, and one of them had stopped wanting a baby?
Such questions have been raised again by the bitter legal battle between an infertile woman who wants to thaw her frozen embryos for "one last chance" of pregnancy and her former boyfriend, who has refused consent. The European Court of Human Rights has ruled that Natallie Evans cannot use the embryos she made with her ex-partner Howard Johnston unless he agrees. She wants a second hearing, but time is running out: under UK law the embryos must be destroyed in October, when it will be five years since they were made.
The Human Fertilisation and Embryology Authority, which licenses and monitors the 85 clinics carrying out IVF in this country, has told The Independent on Sunday there were 117,619 embryos in storage at the end of 2004. The figure may now be greater.
Embryos for use in IVF are created by mixing eggs taken from the woman with sperm in a petri dish. Any that fertilise are placed in an incubator for three days, during which they divide into eight cells each.
One or two embryos may now be transferred by catheter back to the womb, where it is hoped they will develop into a baby. The others are frozen and stored, usually to avoid the woman having to go through the invasive and expensive process of egg retrieval again. Natallie Evans's embryos were frozen in 2001 because it had become apparent she had cancer, which would mean the removal of her ovaries.
Ms Evans fought off the cancer. Unfortunately she also broke up with her boyfriend. They had signed the usual agreement that the embryos would not be thawed and used unless both parties agreed to it, but after the split Mr Johnston no longer wanted to father a child with her.
"There will be some people who think I am cold-hearted and my decision monstrous," the 29-year-old admitted yesterday. "But when I have a child I want to be a responsible father, not just some sperm donor who plays no part in his or her life."
Everyone from Vanessa Feltz to the Bishop of Rochester has expressed an opinion on the case, and Laura Walker is no exception. The 38-year-old from Chingford in east London knows neither of the people involved, but she does know how it feels to be childless - she went through 11 cycles of IVF, at a cost of tens of thousands of pounds. The result was Lois and her baby twin sisters, all three of them "frosties".
"I can see the man's point of view," says Mrs Walker, "but if I was that woman I would want to bloody murder him. It must be tearing her apart. How can a man hate a woman so much that he makes a decision like that?"
Hate versus love. Logic versus emotion. Man versus woman. The case has been presented in all these ways, but it is the language used to refer to the embryos that is revealing. Almost everybody has talked as if the fight was over an actual child. Actually, the chances of Ms Evans getting pregnant using one of the embryos is only about 14 per cent.
Science and the law both work on the basis that an embryo at this very early stage is a sub-human scrap of genetic material and only becomes a person later in its development. The majority of people going through IVF probably agree (it does make what they are doing far less morally complicated). But those who have been through IVF or made it happen know that even the clearest of minds can be ambushed by emotion and find themselves personalising embryos.
"Some people ask to take home the ones that have not been used," says Andy Glew, senior embryologist at the Essex Fertility Centre, in Buckhurst Hill. "We make sure that life has been terminated before we let them out of the building, but then we do give couples the embryos in a water-based solution so that they can bury them in the garden, or whatever they need to do."
The laboratory at this clinic, one of the best in the country, is no bigger than a domestic kitchen. It looks like one, with work surfaces and cupboards that might have been bought from MFI. The incubator resembles a fridge, and the five cannisters tucked away under work surfaces might be for a gas cooker. They actually contain 1,500 embryos, stored four at a time in thin, transparent plastic straws. "Some people forget that we have them," says Michael Ah-Moye, the consultant who leads the clinic. "That is one reason why we charge a fee for storage - as a reminder."
Every year around 27,800 couples in the UK have IVF, and 8,800 babies are born. The baby-making industry is large but the equipment is small, because this work is done in miniature. In the corner of the laboratory, under a hood that controls the quality of air, is a microscope that I looked through nine years ago and saw eight cells pulsating in a dish. That was my eldest son. Possibly. It may not have been - the embryo transfer was being combined with another sort of treatment - but the romantic view remains so tempting, a comfort blanket against the cold, alienating process of making babies without sex. The trouble is that if you allow yourself any belief, religious or instinctive, that life begins at conception, then the creation and freezing of embryos starts to feel disturbingly like Aldous Huxley's Brave New World. Even if these frozen ones are not deemed to be alive now, some of them will be one day - so what implications will freezing have for their futures?
The Medical Research Council says the risks of genetic damage and cancer in babies born through IVF may not be fully appreciated until more of them have grown into adulthood. The first test-tube baby was born in 1978. Two years ago the fertility specialist Lord Winston said that freezing embryos appeared to lead to changes in a gene whose job was to suppress cancer. "I'm not saying we should stop any of these treatments," he said, but he added that more research was needed into their effects.
None of which concerned Laura Walker very much during the 12 years she was having IVF. "I just felt like a failure because I could not have children," she says. "You get tunnel vision. You don't care about the process and you don't think about the future because it all hurts too much. You try anything, whatever the consequences, because you don't think anything is going to work."
She and her husband David began trying for a baby as soon as they got married. After two ectopic pregnancies they began the cycle of hope and despair that is IVF. One attempt costs around £3,000 at a private clinic. "We didn't keep track of the money," says Laura. "It was too scary. But I would have given up everything for a child."
Lois was eventually conceived at Barts, under a scheme partly funded by the NHS. "I couldn't believe it when she was born," says Mrs Walker. "My best friend came to see me and I kept saying, 'I've got a baby! I've got a baby!' She was like, 'I know!' We were in floods of tears."
The Walkers thought it might be easier to conceive again after Lois. They were wrong. They were about to give up when a friend told them about a new method being pioneered at the Essex clinic. The embryos made from Laura's eggs were grown for five days instead of three, by which time they had divided into 200 cells.
At this stage they are called blastocysts, and since the clinic started transferring them instead of three-day embryos the success rate has trebled. Last year 110 patients had blastocyst transfers at the clinic, and 38 per cent had babies.
Laura Walker was one of them. She cannot believe her luck, as she nurses her 10-week-old girls, Billie and Sydney. "We are blessed," she says, beaming. "I'm more in awe of the process now than ever. All the feelings of hurt have gone. But I remember them, you know? I hurt so deeply for so long. That's why I feel for Natallie Evans so much. It does not work for everyone, but she is not even being given the chance to try."
FROM THE BIG CHILL TO A BABY
How embryos are made, stored and one day - if they survive - may be given life
1. Eggs are created
Fertility drugs stimulate the ovaries into producing more eggs than usual. Their growth is monitored with ultrasound scans and, when ready to be released, they are collected
2. Eggs are collected
The eggs are collected from each ovary using a thin needle. This is either guided through the vagina by ultrasound or it is inserted via a small cut in the abdomen (a laparoscopy), usually under general anaesthetic
3. Sperm is washed
The male ejaculate is spun twice, to separate weak sperm and cellular debris from the rest. A solution is added and the strong sperm which are left in a pellet at the bottom of the centrifuge then swim to the top
4. Sperm meets egg
Eggs are placed in a solution in a petri dish, typically four at a time. Around 250,000 sperm are then introduced to the eggs. In ICSI, a technique used in 44 per cent of cycles, a single sperm is injected into an egg
5. Cells divide
Fertilised eggs are kept in an incubator at 37 degrees centigrade for three days, during which time they divide into eight cells. Some clinics now incubate for five days, creating a blastocyst with around 200 cells (see opposite page)
6. Embryos are frozen
Water is removed from the embryos, which are stored four at a time in thin plastic straws. The temperature is slowly reduced to -196C and the straws kept in a flask filled with liquid nitrogen. Clinics charge around £350 a year to keep one batch
7. Embryos are thawed
Ice crystals disappear as the straw is brought up to room temperature. Embryos are put through the solutions used to freeze them, but in reverse order. Now just tight balls of cells, they are left to expand overnight. It is possible that none of them will have survived this far
8. Embryos are returned
If not destroyed by freezing and thawing, two embryos are injected into the womb through the cervix using a fine catheter. If they implant in the womb and grow, a baby may result. But this only happens in about 14 per cent of embryo transfersReuse content