Meghan, 37, and Harry, 34, announced the pregnancy in October, just as they kicked off their 16-day tour of Australia, New Zealand, Fiji and Tonga.
Meghan's every move has been scrutinized ever since, from her maternity fashion choices to her bump cradling. Through it all, Meghan has kept up a relentless pace of engagements, including the recent announcement of her four charitable patronages.
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As we await the birth of the royal baby -- aka Prince George, Princess Charlotte and Prince Louis's cousin -- here is everything we know so far.
When the baby will arrive
Meghan told a well-wisher during a recent visit with Harry to Birkenhead, Merseyside, that she is due in late April or early May.
When her pregnancy was announced in October, Kensington Palace said only that Meghan was due "in the spring."
Where the baby will be born
The Duke and Duchess of Sussex will be keeping plans for the birth of their baby private, according to a statement released by Buckingham Palace.
Meghan's sister-in-law, Duchess Kate, gave birth to all three of her children at the Lindo Wing at St. Mary's Hospital Paddington in London, where the late Princess Diana also delivered both Prince William and Prince Harry.
Meghan and Harry may also choose to deliver their baby somewhere else in London or somewhere closer to their new home in Windsor.
How the baby's birth will be announced
The Duke and Duchess of Sussex will not make any announcements about the birth until they've celebrated "privately as a new family," Buckingham Palace announced.
"The Duke and Duchess of Sussex are very grateful for the goodwill they have received from people throughout the United Kingdom and around the world as they prepare to welcome their baby," the palace said. "Their Royal Highnesses have taken a personal decision to keep the plans around the arrival of their baby private. The Duke and Duchess look forward to sharing the exciting news with everyone once they have had an opportunity to celebrate privately as a new family."
Harry and Meghan's decision to skip the traditional photo op outside the hospital has drawn backlash from some members of the British press.
"This is the shattering of a tradition that goes back for decades," one journalist told The New York Times. "There is a price to be paid for that, and that price is mockery."
The Sun, a high-profile U.K. tabloid, slammed the Duke and Duchess of Sussex infringing on the public's "royal rights.”
“Keeping the nation in the dark over details, even after the birth, is a bad look for the royal couple,” the newspaper wrote in an April 12 editorial. “The public has a right to know about the lives of those largely funded by their taxes. You can accept that, or be private citizens. Not both.”
Where the baby will live
Harry and Meghan will raise their baby at their newly-renovated home, Frogmore Cottage, an 18th century home on the grounds of Windsor Castle, about 30 miles from London.
Windsor is home to Windsor Castle, the largest occupied castle in the world and a special place for Harry's grandmother, Queen Elizabeth II. Meghan and Harry's wedding last May took place at St. George's Chapel at Windsor Castle.
"Windsor is a very special place for Their Royal Highnesses and they are grateful that their official residence will be on the estate," Kensington Palace said in a statement announcing the move.
How the baby may make history
Harry and Meghan's child could hold dual American and British nationality, a first for a royal baby.
Meghan, a California native, will reportedly still be waiting for her British citizenship application to be approved by the time she gives birth. Kensington Palace said in November that Meghan would retain her U.S. citizenship as she undergoes the process of becoming a British citizen, which can take several years.
"From what I understand, Harry and Meghan will have to acquire documentation for their child to prove U.S. citizenship and it’s not clear if they will do that but of course the option is there," said ABC News royal contributor Victoria Murphy.
Baby Sussex could also be the first mixed race child born into the royal family, although historians are divided.
Some royal historians have pointed out that when Queen Charlotte married King George III in the 1700s, he was believed to have descended from the black branch of the Portuguese royal family. The couple had 15 children, according to the British royal family's website.
Meghan was born to a white father and a black mother and grew up as a biracial child in Los Angeles.
Where the baby will fall in the line of succession
The boy or girl will be seventh in line to the British throne, after its grandfather, Prince Charles, uncle, Prince William, three cousins, George, Charlotte and Louis and its father, Prince Harry.
The baby will not automatically be a prince or princess, but its great-grandmother, Queen Elizabeth II, can step in to give the baby that title.
What leave Meghan, Harry will take after the baby is born
The palace has not yet announced maternity and paternity leave the Duke and Duchess of Sussex plan to take after the baby's arrival.
Being a member of the royal family is not a job that comes with established maternity and paternity guidelines. Both Kate and William took some time off after the births of each of their three children.
It will be up to Meghan and Harry to decide the length of time they take off from public engagements.
Meghan has been busily working throughout her pregnancy, recently announcing her four charity patronages.
Who will support Meghan, Harry as new parents
Meghan's mother, Doria Ragland, lives in Los Angeles, but there will be plenty of room for her to stay at Frogmore Cottage should she travel across the pond to help Meghan, her only child.
Closer to home, the couple will of course have Harry's family nearby in London.
Who the baby's playmates may be
Meghan and Harry's child will have built-in playmates with its cousins, Prince George, 4, Princess Charlotte, 3, and Prince Louis, who will turn one in April, all living nearby in Kensington Palace in London.
There will also likely be family holidays all together at Balmoral, the Queen’s estate in Scotland, and those famous royal Christmases at Sandringham House.