** FILE ** Britain's Prince William and wife Kate, Duchess of Cambridge, leave the King Edward VII Hospital in central London on Thursday, Dec. 6, 2012. The duchess was admitted to the hospital when she suffered acute morning sickness in her pregnancy. She has entered the early stages of labor, it was announced on Monday, July 22, 2013. (AP Photo/Alastair Grant)

Photo by: Alastair Grant

** FILE ** Britain's Prince William and wife Kate, Duchess of Cambridge, leave the King Edward VII Hospital in central London on Thursday, Dec. 6, 2012. The duchess was admitted to the hospital when she suffered acute morning sickness in her pregnancy. She has entered the early stages of labor, it was announced on Monday, July 22, 2013. (AP Photo/Alastair Grant)