Problems with Twins

Two-thirds or three-fourths of identical twins are monozygotic twins so they share a placenta. When you share placenta you share vascularity so the two twins have to share blood supply. Two problems develop as a result of this that have been the focus of a lot effort a UCSF.

 

First is twin-twin transfusion, we have normal fetuses but uneven placental share.  The second are twins that has reversed arterial perfusion, one good twin and one twin that is doing poorly as it does not have a head, or a cervical spine so it is more of a blob tissue (parasitic twin).  The vascular anatomy is not very clearly elucidated for many years until Jeff May Chi a pathologist from Kaiser looked very carefully at anastomoses. Through his research it became very clear that it were deep anastomoses.