Kate Middleton's birthday tomorrow to be 'low-key'?

The Duke and Duchess of Cambridge leave hospital in London where she had been admitted with severe morning sickness last month. Credit: PA

The Duchess of Cambridge celebrates her 31st birthday tomorrow but is unlikely to be partying into the small hours.

As Kate is pregnant, believed to be just over 12 weeks, celebrations are expected to be low-key.

St James's Palace has said the Duchess will be marking her birthday "privately".

Kate is thought to be with her husband William at their home in north Wales where the Duke works as an RAF Search and Rescue helicopter pilot.

A romantic birthday meal at home could be on the cards for Kate who was born at the Royal Berkshire Hospital in Reading, on January 9 1982.