I understand the clear difference between the Mono/Mono, Mono/Di, and Di/Di Twins.

Mono/mono : 1 sac 1 placenta

Mono/Di: 2 sacs 1 placenta same blood supply.

Di/di: 2 sacs 2 placentas.

But here’s where I get lost. You can have a di/di that have placentas that fuse together which can lead to twin to twin transfusion. So does that then make them mono/di if they fuse? Probably a question for my OB but I don’t see him for 2 more weeks and I have my scan Tuesday to find out the type of twins I have.

Just curious if anyone knew the answer.