There's a spooky theory about Kate Middleton's outfit to introduce Prince Louis

(Image credit: 2018 Anwar Hussein)

When the Duchess of Cambridge gave birth to Prince Louis on 23rd April 2018 at St Mary's Hospital, she carried on a royal tradition: introducing the new baby to the world, on the steps of the Lindo Wing. She had previously done so with Prince George and Princess Charlotte.

On this occasion, Catherine wore a red dress with a white lace Peter Pan collar by Jenny Packham. At the time, many compared it to the red outfit worn by Princess Diana when she just gave birth to Prince Harry.

It's true they were very similar styles, especially with the white collar and vibrant hue. Plus, it wouldn't be the first time Kate had paid tribute to her late mother-in-law.

However, Twitter users have since made a spookier comparison: with Mia Farrow in horror movie Rosemary's Baby.

The actress also wore a red dress with lace collar in the movie, which centres around a young wife being tricked into having the devil's baby.

When you look at the outfits side by side, the resemblance is quite uncanny, though I'm pretty sure Kate wouldn't have made the connection.

GET THE LOOK

MARC JACOBS The Berlin polka-dot minidress, £504 at MyTheresa

MARC JACOBS The Berlin polka-dot minidress, £504 at MyTheresa

The Chilling Witch Short Dress, £17 at Amazon

The Chilling Witch Short Dress, £17 at Amazon

Red lace dress, was £108.18 now £54.09 (50% off) at Etsy

Red lace dress, was £108.18 now £54.09 (50% off) at Etsy

Perhaps Jenny Packham took inspiration from the movie, or perhaps not. Either way, you've got to admire the investigative work of royal fans.

Penny Goldstone

Penny Goldstone is the Digital Fashion Editor at Marie Claire, covering everything from catwalk trends to royal fashion and the latest high street and Instagram must-haves.

Penny grew up in France and studied languages and law at the Sorbonne Nouvelle University in Paris before moving to the UK for her MA in multimedia journalism at Bournemouth University. She moved to the UK permanently and has never looked back (though she does go back regularly to stock up on cheese and wine).

Although she's always loved fashion - she used to create scrapbooks of her favourite trends and looks, including Sienna Miller and Kate Moss' boho phase - her first job was at MoneySavingExpert.com, sourcing the best deals for everything from restaurants to designer sales.

However she quit after two years to follow her true passion, fashion journalism, and after many years of internships and freelance stints at magazines including Red, Cosmopolitan, Stylist and Good Housekeeping, landed her dream job as the Digital Fashion Editor at Marie Claire UK.

Her favourite part of the job is discovering new brands and meeting designers, and travelling the world to attend events and fashion shows. Seeing her first Chanel runway IRL at Paris Fashion Week was a true pinch-me moment.