I'm sorry, sweetheart, but you're not my daughter

So said Kimberly Mays' father when she was 10. Now, in the latest twist to America's birth-swap drama, she has been forced to give up her own son. This turn of events was of no comfort to another mother coming to terms with the loss of her child. By David Usborne

At the end of April this year, Kimberly Mays went on a most unusual mission. From her home in Orlando, she travelled to the town of Buena Vista at the foot of the Blue Ridge Mountains in Virginia, to visit a woman she had never met before but with whom she felt a powerful bond. What the woman, Paula Johnson, was going through, Mays was uniquely equipped to understand.

In July last year, Johnson had discovered that her youngest child, Callie, three years old with blue eyes and blonde hair, was not her biological child. Callie's natural parents lived just a few miles away, while the little girl they thought was theirs, who they had called Rebecca, was Paula Johnson's daughter.

Paula expressed unbounded gratitude to Kimberly for visiting. She even took Kimberly to visit Rebecca, her biological daughter. "Kimberly is the only person in the world who can tell me how my daughter can feel," she said.

Kimberly Mays was 10 when her father sat her down in the front room of their house in Florida and told her she was not his little girl. Kimberly had been switched at birth and was somebody else's daughter. What followed for Kimberly were 10 years of confusion in the glare of the press, whose hunger for details of her plight was insatiable. She ricocheted between two homes - one she had grown up in, the other that was suddenly hers by right - unable to settle in either.

Mays, now 20, eventually did settle down. In 1997, she married her boyfriend, Jeremy Weeks, and the couple had a child of their own. They called him Devin, and in the maternity ward Mays joked with nurses that the boy was never to leave her chest until both were allowed home.

The tale of Kimberly Mays began in 1978 at the Hardee Memorial Hospital in Wauchula, Florida. Robert Mays and his wife Barbara went home the proud parents of a newborn girl, Kimberly. They had been trying for a child for eight years and Kimberly was a miracle for them. At the same time, another couple, Ernest and Regina Twigg, also went home with an infant girl. They named her Arlena.

Arlena, however, was sickly from the start with a congenital heart defect. In 1988, aged 10, she underwent high-risk open-heart surgery, which she did not survive. Blood tests done before the operation revealed that her blood type was different from her parents'. Realising that Arlena was not theirs biologically, and suspecting that their own child had been misplaced at Hardee, the Twiggs began the hunt for their natural daughter. With the hospital's help, they identified Kimberly, who Robert Mays had raised alone (his wife had died when Kimberly was just two). The truth emerged: Arlena and Kimberly had been switched at the hospital. How that occurred has never been established.

Robert Mays recalled explaining the truth to his daughter when she was 10. It was the day that Kimberly's life first slipped its axis. "Once upon a time, about 10 years ago," he began - in the tradition of all good fairy tales - "two little girls were born in a hospital not far from here..." Mays described how the security that Kimberly had felt all her life drained from her features. "Daddy," she said, "are you saying you're not my Daddy and I have to move away?"

Nothing Mays said could stave off the years of turmoil to follow. Both families were awarded multi-million-dollar settlements by the hospital, but the Twiggs also sued for custody. Finally, visitation rights were agreed and for four years, Kimberly spent more and more time with Ernest and Regina. Then, in 1993, she declared she wanted the Twiggs out of her life. She went to the courts to sue for what amounted to a divorce from her biological family. At the end of a massively publicised seven- day civil trial, the judge granted the petition and denied the Twiggs all further parenting and visitation rights.

Even then, the painful saga was not over. In March 1994, the adolescent Kimberly ran away from Mays to a YMCA shelter, alleging that he had sexually abused her from the age of seven - an allegation she later withdrew - and asking to be returned to the Twiggs. She even adopted the name Arlena Twigg, after her baby-switch "twin" who had died. Kimberly was eventually reconciled with Mays and moved back home.

The agony of Paula Johnson also started in a hospital: the University of Virginia Medical School in Charlottesville. How her baby came to be switched is still a mystery. The unravelling of Callie and Rebecca's lives began in July last year, when Paula Johnson's ex-boyfriend refused to pay child maintenance. To confirm his parentage, the court ordered a DNA test, which proved not only that the boyfriend was not the baby's father, but Paula was not her mother. Just like the Twiggs 10 years earlier, Paula felt compelled to discover the identity of her real daughter.

That little girl was Rebecca Chittum. Just as Paula's search was bringing her closer to Rebecca and her two young parents, Kevin Chittum and Whitney Rogers, another tragedy occurred. Driving on a rain-slicked interstate to a country fair on 4 July, Chittum and Rogers lost control of their car, and died in a crash.

The families of the dead couple assumed responsibility for little Rebecca. Two weeks after the accident, a doctor from the University came to the house. He said that an investigation had revealed that Rebecca had not in fact been the biological child of the dead couple. There was disbelief. "I laughed," Kevin Chittum's sister, Roxanne, recalled. "I had held her at her birth and watched the cord being cut." Only when family members were shown photographs of the child's mother, Paula Johnson, were they forced to acknowledge the truth. The physical resemblance between mother and daughter was unarguable.

Paula wants to keep the newly orphaned Callie but, through lawyers, has hinted that she may also seek custody of Rebecca. She made legal moves last month to block a $2m settlement paid to the Chittum and Rogers families to help them bring up Rebecca. Relations between the two camps have become increasingly frayed.

Now, Kimberly Mays is herself back in crisis. On 3 May, the Department of Children and Families in Florida confirmed that her little boy, Devin, had been taken from the Mays-Weeks home a few days earlier by officers from the agency, and had been placed in foster care.

"Switched-at-birth mother loses child," blared the Florida headlines. No reason for the removal of Devin was made public. Indeed, efforts by lawyers for the Department of Children and Families to have her file opened were scotched by a state judge. An open hearing has been set for early next month. What has gone wrong in the Mays-Weeks household will then become property of the public and of the tabloids. There are three circumstances under which the state can confiscate a child for its parents: neglect, abuse or abandonment.

Neither Mays nor her husband will comment on their new plight. "Kimberly is doing as well as can be expected," her lawyer, Diana Tennis, said. "She's already doing all the things she would need to do to get Devin back." That will include agreeing to a programme drawn up by the state designed to demonstrate that she and her husband are caring properly for the child. The process is likely to be lengthy. It is unlikely that Devin will be returned to his parents at next month's hearing.

Those familiar with the removal of Devin Weeks refuse to draw any link between problems in the home and the mother's traumatic childhood. "You have to remember that the Weeks are a very young couple, and the kind of problems they're having are often seen in young couples," said Yvonne Vassel, a spokesperson for the Department of Children and Families. Child psychology experts note that children involved in baby-switch battles can suffer very deep and long-term damage.

"It affects self-esteem and one's sense of identity," said Nadine Kaslow, a child psychology professor at Emory University in Atlanta. "They become confused about who they are and who they belong to, and they start to wonder what was wrong with them that they were switched at birth. And to learn about this during adolescence can be emotionally overwhelming." Nor would it be surprising, she added, if victims of such trauma passed on their confusion to another generation. "These kids are at a far greater risk of having parenting problems. They find it hard to make a stable home."

The fear that the idea of a baby swap instills in us goes deep, and has been fed by centuries of legend and folklore. In medieval Europe, myths abounded of evil fairies stealing healthy babies and substituting them with ugly and vexed changelings, which parents were advised to beat or throw in a fire so that they might fly home. Romantic tales of princes exchanged with paupers also capture the imagination. Small wonder the press, too, finds fascination in such tales.

When she visited Paula Johnson, Kimberly had meant to reassure her that we are no longer in the era of changelings, happy endings are still possible. Today, with Mays bereft of her own baby, those words of reassurance must be sounding hollow.