LONDON, ENGLAND - OCTOBER 21:  Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge arrive at Buckingham Palace during a state visit by the President of Singapore Tony Tan Keng Yam on October 21, 2014 in London, England. The Duchess is currently four months pregnant with her second child and along with her husband, Prince William, Duke of Cambridge met the Singaporean President at the start of his four day stay in the UK.  (Photo by Carl Court - WPA Pool/Getty Images)