The pregnant Duchess of Cambridge has hosted a round-table discussion on maternal mental health.

Kate, who is expecting her third child, held the private meeting, which was not announced beforehand, at her London home Kensington Palace, with The Royal Foundation.

Kensington Palace, who tweeted a photo of a smiling Kate, joining guests at the discussion, said: “The Duchess is keen to develop an understanding of the issues surrounding maternal mental health, and to learn what support is available.”

The Palace also revealed that the Duchess is to visit the Hornsey Road Children’s Centre – the engagement she was forced to postpone in September on the day the forthcoming royal baby was announced.

As with her previous pregnancies, Kate has been battling hyperemesis gravidarum – a condition which causes severe sickness in pregnancy.

Two months on, she is finally well enough to make it to the London children’s centre on November 14 to learn more about Family Action’s perinatal mental health services and meet parents who have been helped by the charity.

On Wednesday the Duchess met experts from the Maternal Mental Health Alliance, the Anna Freud National Centre for Children and Families, Family Action, King’s College London, the Best Beginnings charity which aims to reduce child health inequalities, and the Royal College of Obstetricians & Gynaecologists.

At least 20% of women are affected by mental health problems during pregnancy or in the first year following the birth of a child, the Palace said.

Kate has, in the past, described her life as mother to Prince George and Princess Charlotte as a “rewarding and wonderful experience”, but admitted that it had been a “huge challenge” at times that has left her feeling a “lack of confidence” for periods.

She opened up about her maternal struggles in March as she attended the launch of a series of films aimed at helping new parents cope with depression and other mental health issues.