News of her miscarriage comes after Meghan, Duchess of Sussex revealed in November last year that she had miscarried the previous July.
Writing in an article for the New York Times she described feeling “an almost unbearable grief”, adding: “I knew, as I clutched my firstborn child, that I was losing my second.”
She went on to describe how she watched “my husband’s heart break as he tried to hold the shattered pieces of mine”.
The Duchess wrote that “loss and pain have plagued every one of us in 2020” and urged people to “commit to asking others, ‘are you OK?'” over the Thanksgiving holiday in the US.
At the time a source close to the Duchess said the couple wanted to talk about what happened to her after having come to appreciate how common miscarriage is.
That came shortly after the US model Chrissy Teigen, the partner of singer John Legend, drew both praise and criticism on social media for posting a photograph of herself in hospital taken after she had suffered a miscarriage.
The striking black and white image showed her sitting on a hospital bed in tears. In the accompanying caption Ms Teigen described being in “the kind of pain we’ve never felt before”.
In April last year Mrs Johnson, who was in the late stages of a previous pregnancy at the time, revealed she was suffering from Covid symptoms and was isolating in Camberwell, south London, with the couple’s dog Dilyn.
At the time she tweeted: “I’ve spent the past week in bed with the main symptoms of coronavirus. I haven’t needed to be tested and, after seven days of rest, I feel stronger and I’m on the mend.
“Being pregnant with Covid-19 is obviously worrying. To other pregnant women, please do read and follow the most up-to- date guidance which I found to be v reassuring.”