The Duchess of Cambridge will speak about the importance of maternal mental health at the launch of a series of films promoting the psychological well-being of parents and their children.
Kate will give a short speech as the Out of the Blue educational films are released, providing an invaluable resource for expectant parents and those with infants and toddlers.
Best Beginnings, a charity which works to help parents give their children the best start in life, has produced the films.
It is a charity partner of the Duke and Duchess of Cambridge and Prince Harry's Heads Together mental health awareness campaign.
Health campaigners, academics and professionals will also attend the launch being held at the Royal College of Obstetricians and Gynaecologists in central London.
The Duchess will watch one of the films and also say a few words before introducing a couple who will talk about their experience of post-natal depression.
The Out of the Blue film series explores a range of mental health conditions from low mood and anxiety to more severe forms of depression through real-life stories.