Will and Kate's third baby announcement inexplicably missing from 2017 royal highlights video

Will and Kate’s announcement was left out of the video. (Getty)

The royal family had a big year last year, from Prince George starting school to the Duke of Cambridge’s last shift as an air ambulance pilot in July. Not to mention Prince Harry’s engagement.

So to celebrate, Kensington Palace uploaded a touching video to Instagram to commemorate all the highlights of the past 12 months.

Featuring heartwarming photos of all our favorite royals, the minute-long video touched on Harry and Meghan’s wedding announcement, Prince George and Princess Charlotte dressing up for Aunt Pippa’s wedding, and the newly released photos of late Princess Diana.

Prince George and Princess Charlotte at Aunt Pippa’s wedding. (Getty)

But viewers were quick to point out that one of the biggest royal stories of the year was missing: the Duke and Duchess of Cambridge’s third baby announcement.

One viewer commented: “What about William and Kate announcing baby number 3?! All very beautiful moments, can’t wait to see the exciting moments of 2018.”

While another said: “How could the Kensington Palace account make four of these year end retrospectives and not once include the fact that the Duke and Duchess of Cambridge are expecting in April? What a strange oversight!”

Others pointed out more events the palace should have included: “Where is the highlight of Queen Elizabeth and Prince Philip’s 70th wedding anniversary???”

Will and Kate made their baby announcement in September, despite the fact that the child is not due until April.

The reason for this is that Kate is suffering again from hyperemesis gravidarum — a severe type of morning sickness.

However, other viewers were delighted with the video, commenting: “Thank you William, Kate, Harry, Meghan, George, Charlotte….. for this wonderful and amazing year 2k17 i’m too exited [sic] for 2k18.”

Another said: “So happy for Harry and meaghan !! [sic] Love the tribute to Diana was well deserved!! ”

Read more from Yahoo Lifestyle:

Follow us on Instagram, Facebook, and Twitter for nonstop inspiration delivered fresh to your feed, every day.