External Link - Source: Washington Post
A DNA test would soon reveal the truth: One of the “twins” was actually Allen and Jasper’s biological son. Despite using condoms, they had apparently conceived the child after becoming pregnant with the Lius’ baby, in what is believed to be an extremely rare case of superfetation. The condition — in which an already pregnant woman conceives another child — is so rare that alleged cases are usually treated with skepticism. In a widely publicized 2009 case of a pregnant Arkansas woman becoming pregnant “again,” Karen Boyle, a reproductive medicine specialist, told ABC News that there were only about 10 reported cases of superfetation in medical literature.