Dicephalic parapagus twins Hensel, born in Minnesota in 1990, are another instance of dicephalus parapagus twins who grew up. They were born with two functional arms, plus a vestigial third arm, which was surgically removed. Each twin has her own complete head, heart and spine, and controls one arm and one leg. They learned to walk around the same age as average children, went on to attend school, learn to drive, play sports, and completed courses at college. Twin girls conjoined like the Tocci brothers, with four arms and two legs altogether, were born in Turkey in 2000. As with the Toccis and
Monochorionic twins Monochorionic twins Monochorionic twins are monozygotic (identical) twins that share the same placenta. If the placenta is shared by more than two twins (see multiple birth), these are monochorionic multiples. Monochorionic twins occur in 0.3% of all pregnancies. 75% of monozygotic twin pregnancies are monochorionic; the remaining 25% are "dichorionic diamniotic". If the placenta divides, this takes place after the third day after fertilization. Monochorionic twins generally have two amniotic sacs (called Monochorionic-Diamniotic "MoDi"), but sometimes, in the case of monoamniotic twins (Monochorionic-Monoamniotic "MoMo"), they also share the same amniotic sac. Monoamniotic twins occur when the split takes place after