Synorchidia

Synorchidia is a pathology in which two (usually opposite-sex) fetuses are located in one individual amnion, connected by a system of umbilical cords and surrounded by a common placenta. Such fetuses can be one or two twins (mono- or dizygotic). The diagnosis of “synorchia” stipulates that the singleton bladder space is divided into two isolated chambers by umbilical cords.

Synorchia is determined with certainty only by ultrasound at 32 weeks or later: otherwise, medical errors are possible. Under natural conditions, the fetus can develop normally inside one amnion due to the fact that part of the amniotic fluid can flow through the cavities of the connections into both bladders. If the discharge is limited and asymmetrical, then ultrasound may show isotrophy of the fetuses, multiple cysts on the right side of the brain, renal cysts in one of the fetuses and partial agenesis or atresia of the kidney in the other. The term “synorch” can be used in relation to individual systems of the body in the case of a malformation of two identical embryos. The same group of terms applies to paichosinoralia.