Craniopagus twins is comparable to our normal appendages and that their bodies have obvious overlapping physically and psychologically. Because most cases of craniopagus twins are unique, the research outlining general connections between craniopagus twins is limited. However, this example provides insight into the effects of a union between twins who essentially share the same sensory relay system in the thalamus. Conjoined twinning is one of the oldest known birth defects in history and examples with human’s fascination with twins is extremely evident throughout historical literature. The Gemini constellation, known in Greek mythology as Castor and Pollux, is arguably one of the best
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