Vasa Previa

Vasa previa is an uncommon placental condition that carries with it high fetal mortality.^[269] It occurs in pregnancies with a velamentous insertion of the umbilical vessels so that they run through amniotic membranes traversing between the fetal presenting part and the cervical os. These vessels have little support and are very susceptible to trauma during labor. A diagnosis of vasa previa is suspected when vaginal bleeding occurs immediately on rupture of the amniotic membranes and is accompanied by FHR abnormalities. The bleeding in vasa previa is fetal rather than maternal in origin; only a small amount of blood loss may result in fetal demise unless the problem is recognized quickly and an emergency cesarean section can be performed immediately.^[270] Because of the true emergency of this situation, the fastest anesthetic technique should be used for cesarean section. For most patients (and most anesthesiologists), this would be general anesthesia.