this happened to someone I know except she was in her teens when it was discovered. The doctors thought she had some kind of growth or tumor and realized it was the fetus of her twin during surgery. I never completely believed her until now actually
I agree - there was no 'giving birth' the parasitic dead fetus was removed so the baby could live is all.
http://embryo.asu.edu/pages/parasitic-twins "Before scientists began looking at parasitic twin development and its associated conditions, individuals with parasitic twinning often worked in side-shows and circuses. For example, Betty-Lou Williams, born in 1932, had a parasitic twin with two legs and an arm with three fingers that extended from her torso. Williams also had an underdeveloped head imbedded inside of her torso that was discovered in an autopsy. Until she died at twenty three years-old, Williams worked for Ripley’s Believe it or Not?! to make enough money to send her siblings to college. Other examples include George Lippert, whose right leg branched into two, and who worked for P.T. Barnum’s circus at the end of the nineteenth century, and Francesco Lentiini, who also had three legs and earned money by kicking soccer balls with them in shows during the first half of the twentieth century."