Ischiopagi of monozygotic twins. However, studies have shown that these disturbances must happen at critical times in the pregnancy for the conjoined twins to develop. Conjoined twins are at high risk to being stillborn or dying shortly after birth. In some cases, a healthy twin and a parasitic twin are born. The parasitic twin has no hope for survival and dies and is then surgically separated from its twin. Depending upon how the twins are attached and what is shared among them, complications can arise from surgically separating the live twin from the dead twin. In Ischiopagus cases, the children share
Monoamniotic twins Monoamniotic twins Monoamniotic twins are identical twins that share the same amniotic sac within their mother’s uterus. Monoamniotic twins are always identical, always monochorionic and are usually termed Monoamniotic-Monochorionic ("MoMo" or "Mono Mono") twins. They also share the placenta, but have two separate umbilical cords. Monoamniotic twins develop when an embryo does not split until after formation of the amniotic sac, at about 9-13 days after fertilization. Monoamniotic triplets or other monoamniotic multiples are possible, but extremely rare. Other obscure possibilities include multiples sets where monoamniotic twins are part of a larger gestation such as triplets, quadruplets, or more. Monoamniotic