The Health Practitioners' Disciplinary Tribunal has been told that a midwife went on holiday and let a pregnancy continue to 43 weeks, resulting in a stillbirth.
Monique Kapua, of Northland, is charged with professional misconduct.
The tribunal heard on Monday that the baby, called Felix, was dead when his mother gave birth to him 21 days late.
The mother told the tribunal how she desperately wanted to start a family and knew little about pregnancy.
She says she was completely in awe of what she thought was Ms Kapua's knowledge and trusted the midwife with her baby's life.
The mother told the tribunal that Ms Kapua never carried out standard tests during the pregnancy or, when she was severely overdue, discussed the danger of a prolonged pregnancy.
The mother says she was shocked when her midwife went on holiday without notice after the baby's due date.
The baby was stillborn after Ms Kapua returned to work.
Theo Baker, director of proceedings for the Health and Disability Commissioner, says Ms Kapua did not discuss the risks of a prolonged pregnancy, or the prospect of inducing the baby.
Ms Baker says Ms Kapua went on holiday on short notice after the due date and did not organise another midwife.
