Britain's Prince William and Kate, Duchess of Cambridge wave holding their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (AP Photo/Kirsty Wigglesworth)
Britain's Prince William and Kate, Duchess of Cambridge wave holding their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (AP Photo/Frank Augstein)
Kate, Duchess of Cambridge with their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (John Stillwell/Pool photo via AP)
Britain's Prince William and Kate, Duchess of Cambridge carry their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (AP Photo/Frank Augstein)
Britain's Prince William and Kate, Duchess of Cambridge with their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (AP Photo/Kirsty Wigglesworth)
Kate, Duchess of Cambridge with their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (John Stillwell/Pool photo via AP)
Britain's Prince William and Kate, Duchess of Cambridge with their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (AP Photo/Kirsty Wigglesworth)
Britain's Prince William and Kate, Duchess of Cambridge with their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (John Stillwell/Pool photo via AP)
Britain's Prince William and Kate, Duchess of Cambridge with their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (John Stillwell/Pool photo via AP)
Britain's Prince William and Kate, Duchess of Cambridge wave holding their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (AP Photo/Kirsty Wigglesworth)
Britain's Prince William and Kate, Duchess of Cambridge wave holding their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (AP Photo/Kirsty Wigglesworth)
Britain's Prince William and Kate, Duchess of Cambridge with their newborn baby son as they leave the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. The Duchess of Cambridge gave birth Monday to a healthy baby boy — a third child for Kate and Prince William and fifth in line to the British throne. (John Stillwell/Pool photo via AP)
Town Crier Tony Appleton announces that the Duchess of Cambridge has given birth to a baby boy outside the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. Kensington Palace says the Duchess of Cambridge has given birth to her third child, a boy weighing 8 pounds, 7 ounces (3.8 kilograms). (AP Photo/Kirsty Wigglesworth)
Town Crier Tony Appleton announces that the Duchess of Cambridge has given birth to a baby boy outside the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. Kensington Palace says the Duchess of Cambridge has given birth to her third child, a boy weighing 8 pounds, 7 ounces (3.8 kilograms). (AP Photo/Frank Augstein)
Town Crier Tony Appleton announces that the Duchess of Cambridge has given birth to a baby boy outside the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. Kensington Palace says the Duchess of Cambridge has given birth to her third child, a boy weighing 8 pounds, 7 ounces (3.8 kilograms). (AP Photo/Kirsty Wigglesworth)
Town Crier Tony Appleton announces that the Duchess of Cambridge has given birth to a baby boy outside the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. Kensington Palace says the Duchess of Cambridge has given birth to her third child, a boy weighing 8 pounds, 7 ounces (3.8 kilograms). (AP Photo/Tim Ireland)
Town Crier Tony Appleton announces that the Duchess of Cambridge has given birth to a baby boy outside the Lindo wing at St Mary's Hospital in London London, Monday, April 23, 2018. Kensington Palace says the Duchess of Cambridge has given birth to her third child, a boy weighing 8 pounds, 7 ounces (3.8 kilograms). (AP Photo/Tim Ireland)