Velamentous inseion of the cord is associated with an increased risk for:
With velamentous inseion of the cord, the umbilical vessels separate in the membranes at a distance from the placental margin, which they reach surrounded only by amnion. It occurs in about 1% of singleton gestations but is quite common in multiple pregnancies. When fetal vessels cross the internal os (vasa pre), rupture of membranes may be accompanied by rupture of a fetal vessel, leading to fetal exsanguination.