A pregnant woman stole the identity of another expectant mother to try to prevent her own baby being taken into care.
The 24-year-old woman, who has not been identified, had previously had three children removed from her and placed in the care of the local authority.
When she went into labour last August the woman lied to staff at Walsall Manor Hospital that her name was Kay Costin. The woman claimed her pregnancy records had been left with a midwife and provided enough personal information to convince staff of her identity. After the birth, she was then able to leave with her newborn baby.
A leaked document from the hospital said the identity details were taken from a social-networking site. But Kay has denied making her personal details - address, date of birth, GP's name - publicly available.
"I think she knows me, I think it was someone I was friends with, but we haven't been told who it is," 24-year-old Kay told the BBC.
Kay only discovered that her identity had been stolen when a midwife arrived at her door asking to see her baby, despite the fact Kay was still pregnant.
Kay, whose daughter Breah was born in October, said she would like an apology from the hospital for the 'distress' she went through, which she believes caused her to need an emergency caesarean.
"I was scared because I thought someone was following me," she told the Express & Star. "We were locking the doors, I was scared someone had gone through my bin.
"It should not have been allowed to happen, there should have been more done to stop it."
When Breah was born, Kay and her husband Michael couldn't register the birth because the other woman's baby had been registered in Kay's name.
The woman who stole Kay's identity has since had her own baby taken away, but no charges were pursued.
The Walsall Healthcare Trust said it had carried out an investigation into the incident and has now strengthened its procedures for admitting women in labour and how new mothers and their babies are discharged.
The Trust said anyone turning up without their notes would need to have their identification formally confirmed by the hospital, social services and the police before being discharged.
Richard Kirby, the Trust's chief executive, said: "Although this is a very rare occurrence, the learning from this incident has been of value across the organisation and strengthened our procedures for admission and discharge, ensuring that patients have been fully identified."