During pre-birth meetings Ms Thomson told the teen, referred to as 'Ms B' in the decision, that she could be "looked down on" at antenatal classes because of her age, and that Ms Thomson would teach her instead.
But she failed to ensure the young mother understood labour, a birth plan, or how to care for a newborn.
On January 15, 2012, when Ms B started labour and her mucous plug fell out, and she had to search the internet to understand what was happening.
Ms Thomson was phoned several times during labour, but did not attend until she was told the baby's head had already appeared.
After the birth the umbilical cord was cut with kitchen scissors, as she had not bought scissors with her.
After checking Ms B's perineum she told the new mother she had a 'tiny tear'. She advised her to "be ladylike" and keep her legs together, and change her pads often.
She was given no information about preventing infection, or advice on breastfeeding, which Ms B found very painful.
Over the following weeks, Ms Thomson several times visited the young mother, who was in increasing pain and having continued difficulty breastfeeding.
She had resorted to tying her thighs together with a dressing gown cord so the wound would not pull open.
The infected tear was causing pain, dizziness and she could barely walk, but Ms Thomson did not refer her to a doctor.
When Ms B finally went to an after-hours GP on February 10, the doctor found she had an infected second-degree tear.
She was admitted to Wairau Hospital for intravenous antibiotics and surgery, which included cutting away infected tissue and reconstruction.
The midwife was found to have failed to provide an appropriate standard of care.
A claim for damages and costs was settled between the parties. The case was brought before the tribunal after a Health and Disability Commissioner investigation found Ms Thomson had breached the mother's rights.
