The Duchess of Cambridge has been celebrating her 31st birthday on Wednesday, 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.
But there are a number of things off the menu now she is pregnant, with the baby expected in either June or July.
Mould-ripened soft cheese, pate, and raw or partially cooked eggs are to be avoided by expectant mothers, according to the NHS website.
The Duchess has been suffering from a rare form of pregnancy sickness known as hyperemesis gravidarum, that causes long bouts of nausea and vomiting.