The black and white snap, which was shared by photographer Misan Harriman, sees Meghan, 39, wearing an off-the-shoulder dress as she cradles her one year old son Archie in her arms.
Prince Harry, 36, stands behind her, holding his pregnant wife and their son as he rests his forehead on her head.
The photographer, who also took the original snap of them for their pregnancy announcement, posted it on his personal Instagram account.
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In the caption, he wrote: “What wonderful news to celebrate on International Women’s Day!
“Congratulations my friends, and welcome to the #girldad club H,” followed by a red heart emoji and the hashtags #internationalwomensday, #womenshistorymonth, #remoteshoot, #shotonipad, #shotbymisan, #itsagirl and #girldad.
It comes as ITV prepares to air the couple’s tell-all interview with Oprah Winfrey tonight.
During the interview, Meghan revealed that she had suicidal thoughts when she was five months pregnant because of the stress surrounding royal life.
As she broke down in tears, Meghan told Oprah: “I just didn’t see a solution. I didn’t want to be alive anymore.”
She added she “couldn’t be left alone” during her pregnancy with first child Archie, saying it was “a real and frightening and constant thought” but her husband Harry “cradled” her.
The soon-to-be mum-of-two also claimed Prince William’s wife Kate Middleton made her cry days before her wedding to Harry.
When asked by Oprah about the tabloids’ claims Meghan had made Kate cry days before the royal wedding, the Duchess of Sussex said: “No, the reverse happened.”
She added that she “didn’t want to be disparaging to anyone“ but Kate was “upset about something“ over an issue with a flower girl dress.
Prince Harry and Meghan Markle
Meghan said the timing of the issue was especially upsetting amid the uncertainty over whether her father Thomas Markle would attend the wedding.
She added that the Duchess of Cambridge “ took accountability“ after Meghan was brought to tears but insisted there was no confrontation between the pair. Meghan also added that she will not go into to detail about it because Kate apologised.