In a moving account written for the New York Times, Meghan reveals how she lost her unborn baby in July while she and husband Harry were living in Los Angeles.
In the article, entitled Losses We Share, she describes how she was looking after he son Archie when she felt a sharp pain.
She wrote: "I dropped to the floor with him in my arms, humming a lullaby to keep us both calm, the cheerful tune a stark contrast to my sense that something was not right.
"I knew, as I clutched my firstborn child, that I was losing my second.
"Hours later, I lay in a hospital bed, holding my husband’s hand. I felt the clamminess of his palm and kissed his knuckles, wet from both our tears. Staring at the cold white walls, my eyes glazed over. I tried to imagine how we’d heal."
Meghan, 39, goes on to describe candidly how, following her loss, she tried to keep a “brave face” in public.
She refers to an interview with journalist Tom Bradby, filmed during her and Harry’s trip to South Africa, when he asked her how she was doing and she answered: “Thank you for asking. Not many people have asked if I’m OK.”
She writes: "I answered him honestly, not knowing that what I said would resonate with so many — new moms and older ones, and anyone who had, in their own way, been silently suffering.
“My off-the-cuff reply seemed to give people permission to speak their truth. But it wasn’t responding honestly that helped me most, it was the question itself.”
Meghan says she was sitting in a hospital bed watching her “husband’s heart break” when she realised that the only way to heal was to ask herself “Are you OK?”.
An estimated one in four pregnancies ends in a miscarriage according to the charity Tommy’s, which funds research into miscarriages, stillbirths and premature births. Most women lose their babies during the first 12 weeks of pregnancy.
But Meghan describes how the conversation around miscarriage remains “taboo, riddled with (unwarranted shame)" and “perpetuates a cycle of solitary mourning”.
“Losing a child means carrying an almost unbearable grief, experienced by many but talked about by few," she writes.
“In the pain of our loss, my husband and I discovered that in a room of 100 women, 10 to 20 of them will have suffered from miscarriage."
Last month, model and entrepreneur Chrissy Teigen was praised for sharing pictures from hospital after she suffered from a miscarriage.
Teigen revealed on social media that she and husband John Legend had lost their son, named Jack, who was delivered at 20 weeks.
The mother-of-two said she “absolutely knew I needed to share this story” and added that the “photos are only for the people who need them”.
The Queen’s granddaughter Zara Tindall also suffered two miscarriages before having her second child. The Countess of Wessex lost her first baby in December 2001 when she was airlifted to hospital after suffering a potentially life-threatening ectopic pregnancy.
The duchess goes on to reflect on the trials of 2020, saying that the year’s events have brought many “to breaking point”. She notes the “loss and pain” of those who have lost loved ones to Covid-19, and refers to the wave of Black Lives Matter protests, sparked by the deaths of George Floyd and Breonna Taylor.
Meghan ends the article by encouraging people to ask others how they are doing, inviting men and women to “take the first steps towards healing”.
She writes: “We have learned that when people ask how any of us are doing, and when they really listen to the answer, with an open heart and mind, the load of grief often becomes lighter — for all of us. In being invited to share our pain, together we take the first steps toward healing.”
Women’s organisations and charities praised Meghan for highlighting the reality of miscarriage.
The Duke and Duchess of Sussex had openly shared their hopes of having two children to complete their family. It was no secret they dreamed of welcoming a new addition – a baby brother or sister for Archie Mountbatten-Windsor.
Harry told activist and chimpanzee expert Jane Goodall in 2019 that he would only have two children for the sake of the planet.
When Dr Goodall said: “Not too many,” the duke replied: “Two, maximum.”
The Sussexes were over the moon to welcome son Archie on May 6 2019. Harry described Archie’s birth as “the most amazing experience I could ever have possibly imagined”.
Introducing the two-day-old to the world at Windsor Castle, Meghan said: “It’s magic, it’s pretty amazing. I have the two best guys in the world so I’m really happy.”
She added: “He has the sweetest temperament, he’s really calm.”
The duke and duchess have been protective of Archie’s privacy. When he arrived they declined to confirm where he was born, although his birth certificate later revealed he arrived at the private Portland Hospital in London.
Archie’s christening was also a private affair, like most royal baptisms, but Harry and Meghan did not release the names of his godparents.
The duchess once described motherhood as being on her “bucket list”, while Harry often said he would love to have children, particularly after the Duke and Duchess of Cambridge had their own.
Harry and Meghan first met on a blind date in July, 2016 after they were introduced by a mutual friend. Nearly two years later Harry proposed to the Suits actor and they were married at Windsor Castle in May, 2018.
As the first Royal Wedding in seven years, 29 million people in the US and nearly 18 million in the UK stopped what they were doing to watch the Duke and Duchess of Sussex declare their love for one another.
Earlier this year the couple revealed they would be stepping back as senior members of the Royal Family.
The announcement came after Harry issued a damning statement against the media accusing sections of the press of bullying his wife.
Harry and Meghan said they would split their time between the UK and North America and work to become "financially independent" in a bid to "provide our family with the space to focus on the next chapter".