Up to 72 hours (separation up to the morula stage), the twins are
dichorionic, diamnionic. There are two placentas and two sacs. This is the
lowest risk of all monozygotic twins.
Between 4–8 days (separation at the blastocyst stage), the twins are
monochorionic, diamnionic. There is one placenta and two sacs. A specific
additional complication is twin–twin transfusion, which develops in 15% of
mono-di twins. The twins share a single placenta but do so unequally. The
donor twin gets less blood supply, resulting in growth restriction,
oligohydramnios, and anemia. However, neonatal outcome is usually better.
The recipient twin gets more blood supply, resulting in excessive growth,
polyhydramnios, and polycythemia. Intrauterine fetal surgery is indicated to
laser the vascular connections on the placental surface between the two
fetuses. Neonatal course is often complicated.
kiana
(Kiana)
#1