A senior midwife at the hospital where a woman died after childbirth has told an inquest she and her colleagues were "only human".
Mrs Cabrera's son survived
Mayra Cabrera, 30, died after giving birth to son Zac at the Great Western Hospital in 2004, where she had worked.
Swindon and Marlborough NHS Trust later admitted Mrs Cabrera had had an epidural mistakenly fed into her arm.
Post-mortem tests found the cause of death to be the epidural drug - Bupivacaine - toxicity.
At the inquest in Trowbridge, Gerwyn Samuel, barrister for Mrs Cabrera's husband Arnel, questioned Jeanne Hutchins, a senior midwife at the Wiltshire hospital.
He asked her about six separate safety checks midwives are required to carry out when setting up drips for patients.
The checks are to prevent confusion and ensure no mix-ups with drips occur.
Mr Samuel asked her: "From what you are saying, it is inconceivable that someone could fail on each of these checks?"
Mrs Hutchins disagreed: "It is not inconceivable, because we are only human. These (checks) are designed to prevent it happening."
Wiltshire coroner David Masters made clear that no blame for the error was being apportioned to Mrs Hutchins.
Mrs Cabrera came to Swindon in 2002 from the Philippines to work as a theatre nurse at the hospital.
Wiltshire Police investigated the death but a decision was later taken by the Crown Prosecution Service not to charge anyone.
The hearing continues.