The rights of a child to know its parents are written into international law, but in France that doesn't mean very much.
Here is one of the few countries in Europe where children can be born without officially having any parents. The result is generations of Les Enfants X, and enough sorrow to fill the Seine.
Take Laetitia Buron, for example. When she gave birth, in Nice, on 7 November 1987, a sheet was put over her legs so that she would not see her child – then common practice for women giving birth sous X ("under X"), the law that allows women in France to have a baby and hand it over for adoption without disclosing their identity.
Abandonment ran through Ms Buron's family: both she and her mother were brought up in care. When she became pregnant at the age of 25, a psychiatrist advised her to give it up. Depressed and unsure of herself, she agreed. Ms Buron describes the way her labour was approached by the medical staff as "bordering on the veterinary". When her baby was born she insisted on seeing it, and said she couldn't live without it, but another psychiatrist reproached her. The child went, and 15 days later she tried to kill herself.
By the time she had emerged from the desolation and confusion of having gone through pregnancy, given birth, and yet had no baby, it was too late – the statutory two-month retraction period had passed and there was no way of contacting the child or of getting it back.
It is for people such as Ms Buron, and the children who grow up not knowing whose blood they carry, that campaigners have been fighting. In January, a parliamentary report recommended changing the law, and the government announced a working group would be set up to look into the question. But, eight months on, the group has still not met, and campaigners are now pinning their dwindling hopes on next year's presidential elections.
The roots of the tradition of women having the right to give birth in secret lie deep in French history. The practice was codified during the Revolution, which introduced the principle that abandoned infants would become charges of the state, or pupilles de l'état.
For most of its history, the law has been aimed at shielding the mothers of illegitimate children, and at discouraging infanticide, abortion and the use of any sort of contraceptive practice.
In 1941, the collaborationist Vichy government set out the basis of the modern-day sous X legislation. The law was aimed at creating "adoptable" babies out of wartime transgressions – anything from rape to liaisons between French women and "the enemy".
After the war, the practice continued to serve as a way of getting rid of the casualties of poverty and rigid social mores. From both ends of the social spectrum, young girls were forced by their families to give up the badges of their "dishonour" and make them disappear without trace. Many of the babies who went into care sous X in the late Sixties and Seventies were living proof that society had not yet caught up with the sexual revolution. Today, around 600 children are still being born sous X in France every year.
According to Claude Sageot-Chomel, president of DPEAO, an association which defends the rights of people to know their origins, the law persists because France is fundamentally a conservative country. He argues that the legislation is a way of "manufacturing children without any kin to suit the profitable adoption industry ... There has been a huge amount of Catholic influence on the medical world to defend a woman's right to give birth in secret". He suggests that the state's refusal to acknowledge that a child can have multiple filiations comes from fears that this would open the way to gay adoption and the development of unconventional family structures.
Last month, a law came into force upholding bans on sperm donation to lesbian couples, on surrogate motherhood, and restated that gamete donation must remain anonymous. Some say this legislation will bring the suffering of those born sous X to a new generation.
Today, the sous X law is defended by two unusual bedfellows: feminists, on the basis that it is a woman's right to withhold her identity from her child should she so wish, and Catholics, who argue that it reduces abortion. It is also supported by obstetricians, who insist that, without it, more women would give birth without going to hospital, as well as by organisations that represent adoptive families.
But many of the 400,000 people living in France today who were born under this law say not knowing where they come from denies them part of their identity. Two years ago, the man whom Sabine Menet, now 36, had always believed to be her father committed suicide. Her mother realised that were she also to die unexpectedly, Sabine would inevitably find out the truth for herself. So the day before his estate was due to be settled, she told her daughter that she was not, as she had always believed, the biological offspring of her and her late husband. She had been born sous X.
"It was as though a part of me had known this already, but from that moment I entered into a sort of no-man's-land. I went through a year of depression, during which I realised that all the pillars on which my life had stood were shattered. I lost a lot of weight, and was no longer able to work."
Her family ties started to fall away as her relations, who had known the secret of her birth all along, cut their ties. Even her close relationship with the woman she now knows to be her adoptive mother largely unfurled at what she felt to be an enormous betrayal: "It is the lying that has destroyed me more than the fact of my having been abandoned."
One of the first things Ms Menet says she did after learning of her adoption was to tell her seven-year-old daughter the circumstances of her origin. "I wanted to break the cycle of secrecy," she says. The next was to try to discover where she came from. Along with many adopted children, she insists that in doing this she has no wish to undermine the people she considers to be her parents, but that she just feels a pressing need to know her origins. Ms Menet describes this need as a "genealogical" rather than a "biological" quest.
The first thing Ms Menet was told by the official she approached was: "You can rest assured that this woman has never taken any steps to try to find you." Like many other children born sous X who have tried to track down information about their birth parents, she has come up against an administrative brick wall. In 2002 a new law was passed under which mothers giving birth in secret would be "invited" to leave details of their identity, that of the father, information about their medical histories, and the circumstances of the child's birth. These are put in a sealed envelope to be made available to the child in adulthood. About a third of mothers refuse.
But for people like Ms Menet, born before these new provisions, trying to trace a birth mother can be a hopeless task. All she has been able to find has been a name – Jany Rose – but she has not been able to track this person down, or to establish whether she really is her mother. "I could be born of a rape, or from incest, or out of a beautiful love affair. Nothing could be worse than not knowing."
One of the most frustrating things for children born sous X who attempt to seek out their birth mother is that the information they desire is generally held in a file somewhere. When women exercise their right to give birth sous X, the state generally gathers some facts about them, but refuses to disclose these to the offspring unless it has the mother's consent. Many who defend the rights of children born sous X accuse the authorities of not helping mothers who are often crippled by guilt to rethink their original decision, and of blocking rather than facilitating contact between family members.
Even cases such as that of Dominique Léonard face these barriers: her daughter Laura developed multiple sclerosis when she was studying for her baccalaureate and needs to know her mother's medical history in order to receive the correct treatment. Mrs Léonard was told by the adoption agency that had dealt with her case: "You can employ all the lawyers on earth, you will never win the right to see your file."
Mr Sageot-Chomel accuses the French state of having abused its dominant position, depriving thousands of people of their autonomy. He says there have been countless cases, particularly in the past, where women judged "unfit" to raise a child were told when they came into maternity wards to give birth: "Don't worry: we know people who will take care of things." Then the woman was anaesthetised while she gave birth, and when she came round she was told that her baby had died. The child would, in fact, have become a pupille de l'état.
Etienne, 29, is one of the happier cases of a child born sous X. His adoptive parents never hid the circumstances of his origins from him, and, through some careful detective work, he managed to trace his birth mother.
After 14 years, Laetitia Buron miraculously managed to trace her daughter. She went to meet her as she came out of school in September 2001. She describes a mutual pleasure at discovering one another, but says her daughter clearly feels a sense of divided loyalties. "I needed to know that my child was OK, that she doesn't need me. I wanted her to know that I am here."
Despite having had three other children, Ms Buron describes not being able to contact her daughter for 14 years as "a bottomless abyss of pain". She says: "We brought them into the world, so we do bear some sort of responsibility towards them."