Monochorionic twin

A monochorionic twin pregnancy is a type of monozygotic twin pregnancy where the twins share a single chorion. Depending on the sharing of the amnion this can be divided into two types.

• monochorionic monoamniotic (MCMA) pregnancy: single amnion
• monochorionic diamniotic (MCDA) pregnancy: two amnions: much more common ~90% 

As they are almost always monozygotic (except in extremely unusual cases), both the twins in a monochorionic twin pregnancy are of the same gender.

Pathological processes that occur almost exclusively in monochorionic pregnancies include:

• twin to twin transfusion syndrome (TTTS)
• twin reversed arterial perfusion (TRAP) sequence 

See also

• multifetal pregnancy

Siehe auch:

• Chorion
• amnion
• monochoriale-diamniote Zwillingsschwangerschaft
• monozygotic twins
• Mehrlingsschwangerschaft
• twin to twin transfusion syndrome (TTTS)
• monochorionic monoamniotic (MCMA) pregnancy
• twin reversed arterial perfusion (TRAP) sequence

und weiter:

• Zwillingsschwangerschaft
• twin-peak sign
• monozygotic twin pregnancy
• MCDA pregnancy
• t sign
• demise of a twin
• lambda sign of twin pregnancy
• dichorionic twin pregnancy
• fetal biometric discordance
• TRAP sequence
• inter twin membrane folding
• twin anaemia polycythaemia sequence