Duchess Kate turns 31, but pregnancy rules out big party

LONDON (AFP) - Prince William's wife Catherine marks her 31st birthday on Wednesday, but her well-documented pregnancy is likely to make it a low-key celebration.

St James' Palace said the Duchess of Cambridge would mark the occasion "privately", and she is understood to be with her husband at their home in north Wales.

Kate was treated last month for a severe form of pregnancy sickness known as hyperemesis gravidarum, whose symptoms include sustained bouts of nausea and vomiting.

The Duchess was admitted to hospital on Dec 3, a development that prompted the palace to announce that she was in the very early stages of pregnancy.