Cressida Bonas is pregnant

Cressida - who previously dated Prince Harry - wrote in The Spectator magazine: "Having conceived through IVF the first time, we were fortunate to have another embryo stored away in a freezer. It is incredible that a tiny cluster of frozen cells, already a life, can survive, suspended in time for years. The science behind the process continues to amaze me."

Cressida also revealed how her second pregnancy differs from her first.

She shared: "This second pregnancy is very different from the first, partly because I've been battling morning sickness. I've never had it before and now feel like I've been swaying on a boat for months."

The actress acknowledged that her second pregnancy has been "less consuming than the first". But Cressida and her husband - who is an estate agent - are now planning to move, as they prepare to welcome their second child.

She said: "I have mixed emotions about leaving the little space we've lived in for so long. I'll have lasting memories of us moving in as newlyweds, building our first home together and having a baby. Yet I'm equally excited at the thought of the next stage."

Cressida previously spoke about her experience of IVF treatment.

The actress was grateful that it worked "the first time" and she thought it was important to share her experience with other couples.

Speaking to The Sunday Times newspaper, Cressida said: "The more we share our stories and lean on others, the lighter the burden of shame that comes with infertility. If it hadn't been for the people who shared their experiences with me, I'd have felt very alone."