New research has shown the survival rate of babies with a rare heart defect is lower for Pacific and Māori compared to European babies.
Congenital critical left heart obstruction is a condition in which the left side of babies' hearts does not form properly.
Survival to one year is highest in European babies at 58%, compared to 44% for Māori and 41% for Pacific.
Researchers say the findings raise the question of whether methods of healthcare provision contribute to inequity in health outcomes.