Conjoined twins are identical twins that are physically connected due to the failure of the fertilized eggs to separate while in the uterus of the mother. The occurrence of conjoined twins is rare.The American Pediatric Surgical Association: Conjoined Twins Conjoined twins often share one or more internal organs. Many conjoined twins do not survive childbirth. Surviving twins often undergo surgical separation, which can be a very dangerous procedure depending on which organs are shared.MayoClinic.com: Conjoined Twins
Preslee and Kylee Wells
Kaylee Hope and Preslee Faith Wells were born on October 25, 2008 in Oklahoma. The girls were born joined at the chest. The Wells twins underwent surgery that would separate them on January 19, 2009. The twins surgery involved splitting their liver.Kfsm.com (OK): Oklahoma conjoined twins separated during surgery (January 19, 2009)