File of the Duchess of Cambridge as she turns 38

Catherine, Britain's Duchess of Cambridge, who is popularly known as Kate, celebrates her 38th birthday on Thursday. Kate has been focusing on early childhood development in her recent work, the period between pregnancy and the age of 5. In November, she spent time at Kingston hospital in southwest London, accompanying midwives on their daily rounds and going into people's homes with them. In an open letter published in December, Kate thanked Britain's midwives, calling their work humbling and crucial. On Christmas Day, she and other members of the royal family attended the traditional Christmas Day church service at the St Mary Magdalene Church in eastern England. On the same day Kensington Palace released a photograph of Prince William, George, 6, Charlotte, 4 and Louis 1, taken by Kate.