A woman who claims her husband's vasectomy has been proved to have failed has demanded an apology from the doctors who carried it out.
A DNA test proved Ryan is Gary McDonnell's son
Julie Garrett, 38, claims staff at St Patrick's Clinic for Reproductive Health in Birmingham had insisted the vasectomy was successful.
She said the clinic's attitude had cast doubt on who fathered the couple's son.
Her partner Gary McDonnell had suffered upset until DNA tests proved he was the father of 14-week-old Ryan, she added.
The couple, from Great Barr, have lodged a formal complaint with the Heart of Birmingham Teaching Primary Care Trust.
Mr McDonnell, 37, had the vasectomy in November 2002 after the birth of the couple's second child.
Miss Garrett said she was left shell-shocked when she fell pregnant last summer.
"After I became pregnant Gary contacted the clinic and underwent tests and they insisted that the vasectomy had been successful," she said.
The couple claim that during a phone call, a member of the clinic's staff told Gary that it was "highly unlikely" that he was the child's father.
Miss Garrett said: "We're lucky that we have such a fantastic relationship because I'm sure a lot of men would have had their suspicions and walked out.
"This could have ripped the family apart.
"What I would like to stress is that this can happen - the medical profession are not always right."
Dr Kulsum Jaffer, a consultant in reproductive and sexual health at the Heart of Birmingham Teaching Primary Care Trust, told a national newspaper that the case had been investigated and evidence strongly suggested that the vasectomy had been successful.
She said she could not comment on a DNA test which the trust had not been involved in.