Kate's appearance on the steps of St Mary's Hospital as she and William proudly showed off Prince Louis of Cambridge to the world has already been the subject of much debate. 

But now the conversation has taken an unlikely turn from the Duchess' ultra-coiffed appearance hours after giving birth, to how much her red maternity smock resembles the dress Mia Farrow wore in the 1968 horror film Rosemary's Baby. 

Comparison photos began circulating on X after eagle-eyed royal watchers pointed out the similarities between the two dresses, which are the same colour and feature the same white lacy Peter Pan collar.

But while Kate's Jenny Packham dress was chosen for the happy occasion of bringing home her third bundle of joy, Mia's had far less pleasant associations for her character, Rosemary Woodhouse, a young housewife who learns her baby is the son of the devil. 

The comparison prompted one user on X to joke: “Not too sure about this Rosemary's Baby remake tbh.”  

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