Princess Diana wore this Catherine Walker maternity dress on a visit to the Isles of Scilly while pregnant with Prince William.Anwar Hussein/Hulton Archive/Getty Images
Diana wore this tastefully bedazzled white gown to a Pavarotti concert while pregnant with Prince Harry, and we are living for the side-eye.Mirrorpix/Mirrorpix/Getty Images
High waisted, Regency-style gowns make the best maternity-wear, especially when paired with a tiara.Princess Diana Archive/Hulton Royals Collection/Getty Images
Princess Diana wore this amazing technicolor maternity coat the day she announced her pregnancy with Prince William in 1982.David Levenson/Getty Images Entertainment/Getty Images
Princess Diana looking very much like she's in a time-traveling production of 'Hamilton.'Anwar Hussein/Hulton Archive/Getty Images
Pretty (and pregnant) in pink.UK Press/UK Press/Getty Images
Did Diana stop at a smart, embellished maternity coat on this 1982 trip to Bristol? No. She went to the extra mile with a jaunty matching hat.Tim Graham/Tim Graham Photo Library/Getty Images
When you're style icon AND pregnant with the future King of England, you can wear a coat made out of a Muppet if you want to.Princess Diana Archive/Hulton Royals Collection/Getty Images
Diana wore this sweet pink frock to cheer on husband Prince Charles at a polo match.David Levenson/Hulton Archive/Getty Images
And here we see another pregnant polo look for the Princess.Princess Diana Archive/Hulton Royals Collection/Getty Images
Diana wore this peach ensemble to the opening day of the Royal Ascot racecourse in 1984.Princess Diana Archive/Hulton Royals Collection/Getty Images
