Vasa previa is a condition in which fetal blood vessels traverse the membranes over or near the internal cervical os, unprotected by the umbilical cord or placental tissue. These unprotected vessels are at risk of rupture when the membranes rupture (spontaneously or during amniotomy), causing fetal hemorrhage and exsanguination. The fetal blood volume at term is approximately 80-100 mL/kg (about 250 mL for a 3 kg fetus), meaning even small-volume hemorrhage can be rapidly fatal. Two types exist: Type 1 involves velamentous cord insertion where umbilical vessels course through the membranes before reaching the placenta; Type 2 involves vessels connecting a succenturiate (accessory) placental lobe to the main placental mass, crossing over the cervix. Risk factors include low-lying placenta, IVF pregnancy, bilobed or succenturiate placenta, and velamentous cord insertion. The clinical hallmark is painless vaginal bleeding with fetal heart rate abnormalities (sinusoidal pattern or bradycardia) at the time of membrane rupture, with maternal vital signs initially stable (the bleeding is fetal, not maternal). The nurse recognizes that vasa previa with ruptured vessels is a fetal emergency requiring immediate cesarean delivery,...