Ischiopagi associated with surgery and reconstruction of organs. Surgery to separate conjoined twins has allowed surgeons to be able to study the mechanisms of embryogenesis as well as the physiological consequences of parabiosis. Depending upon what organs are shared among the twins and if they are surgically separable, usually only one of the twins makes it through the surgery or they both die due to complications either before or during the surgery. Now that successful surgery has been reported and more findings are becoming available due to research and pre-surgery evaluation, better surgery techniques and procedures will be available in the
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