An investigation is under way in Wiltshire after a woman died while giving birth at a hospital in Swindon.
Mrs Cabrera had a heart attack shortly after giving birth
Mayra Cabrera died two years ago after a powerful anaesthetic was injected in her arm instead of her spine.
Managers at the Great Western hospital, where she also worked as a nurse, have only recently admitted liability.
A post-mortem examination found the heart attack she suffered after giving birth was caused by the anaesthetic being administered in the wrong place.
Mrs Cabrera's husband Arnel said: "Suddenly, she just had a gasping in her breath. At that moment I thought something was wrong."
The drug labelled "for epidural use only" was fed through a drip into her arm.
A report says staff noticed the mistake shortly after her death on 10 May 2004, but Mr Cabrera says at the time it was put down to a very rare complication.
"The member of staff told me it happens one in a thousand cases so it's a very rare case. I accepted that because he's a member of the medical staff," he said.
The hospital said it could not comment before the inquest but has said it did admit to mistakes as soon as it was clear through NHS investigations.
"After more than a year you find out that something went wrong and it happens all over again doesn't it - the stress and pain," said Mr Cabrera.
"Honestly speaking, because of what happened and the way it happened this will be engraved in my mind and my heart till the day I die and in the afterlife."