Princess Mary of Denmark is to beome the international patron of the Australian and Danish twin registries.
Her patronage of the Australian Twin Registry, based at the University of Melbourne, and the Danish Twin Registry was announced in a ceremony in Denmark on Tuesday.
AAP reports the Australian Twin Registry supports medical studies involving twins, enabling researchers to study the impact of genetic and environmental factors on health.
Crown Princess Mary was born Mary Donaldson in Hobart and married Crown Prince Frederik in 2004 in Copenhagen.
She is the mother of Prince Christian, Princess Isabella and twins Prince Vincent and Princess Josephine, aged two.