Techniques such as fertility drugs and in vitro fertilization, which are being used more as more older women try to conceive, increase the likelihood of multiple pregnancies. Births of three or more babies have quadrupled in the United States over the past two decades.
Doctors note that multiple pregnancies raise the threat of premature birth and risk to the babies.
Authorities combed the United States and Mexico, but the hunt turned up nothing. Soon, agents from Interpol, the FBI, and the San Diego police, were combing the National Center for Missing and Exploited Children's online database for clues. Genetic tests have since confirmed the girl's identity. It was one of the most dramatic breaks in the center's 13-year history. Who kidnapped the child is still unclear.