Monochorionic diamniotic pregnancy


Representative images demonstrating the appearance of the intertwin membrane in a monochorionic diamniotic (MCDA) twin pregnancy. 

Note single placental mass, with centric insertion of twin 1 umbilical cord and velamentous insertion of twin 2 cord. Velamentous cord insertion may be associated with intrauterine growth restriction; in this case however the pregnancy outcome is unknown.