By the time Cynthia Sigler of Vista, Calif., gave birth to 13-pound Jayden, he had already outgrown all the baby clothes waiting for him at home, she says. Jayden, who was previously expected to be 9 pounds at birth, clocked in at almost twice the weight of his 2-year-old sister, who was 7 pounds at birth. After Sigler\'s successful delivery via Caesarean section Thursday, doctors told her she had given birth to a 13-pound baby boy. \"How\'d he fit?\" she responded. Toward the end of her pregnancy, Sigler said she had been in a great deal of pain. After Jayden joined the world, she suddenly understood why. \"When I saw how big he is, I understood why I was in so much pain,\" she told North County Times (Escondido, Calif.). Dr. Jerald White said Jayden is the largest baby he\'s delivered. Guinness World Records says Jayden falls short of the title, as the largest surviving birth clocked in at a whopping 22 pounds in 1955.