Predicting vaginal birth after caesarean section: Validation of the Grobman model in a New Zealand population.

Background: The decision regarding mode of birth following a primary caesarean section is important. Women may choose an elective repeat caesarean section or a trial of labour in an attempt to achieve a vaginal birth after caesarean (VBAC). The highest morbidity and mortality is associated with those who have an emergency caesarean section following a trial of labour.