A health trust has pleaded guilty to breaching health and safety regulations after a woman was given an epidural anaesthetic in her arm.
Mayra Cabrera died following her son's birth in 2004 after Bupivacaine was mistakenly connected to her arm at Swindon's Great Western Hospital.
Lyn Hill-Tout, chief executive of Great Western Hospitals NHS, entered a guilty plea before Swindon magistrates.
The case was committed to Swindon Crown Court to be heard at a later date.
The court was told how a nurse at the Great Western Hospital had made a fatal error on 11 May 2004.
Mrs Cabrera who had worked as a theatre nurse at GWH had gone through a relatively straightforward birth but required saline to help bring her blood pressure back up.
But a nurse attached the wrong bag of solution to a drip attached to her right arm.
Within minutes, Mrs Cabrera began to feel unwell - and then started to fit. She died soon after.
Swindon and Marlborough NHS Trust - now the Great Western Hospitals NHS Foundation Trust - had previously admitted liability.
An inquest into the 30-year-old's death in February 2008, ruled Mrs Cabrera was unlawfully killed.