T-sign represents what type of twins?
Monochorionic
Lambda sign AKA twin peak sign represents what type of twins?
Dichorionic
The thickness of an intertwin membrane is a good predictor of?
Chorionicity
Twins of different genders are always going to be what kind of pregnancy?
DC/DA
What type of pregnancy will have one yolk sac but two fetal poles?
Monoamniotic
How often do twins occur?
1:100 pregnancies