The classic signs are abdominal pain and vaginal bleeding.
Placental abruption occurs in approximately 1 in 150 pregnancies. This is when the placenta prematurely separates from the walls of the uterus, and it can be a life-threatening emergency.
Common signs of placental abruption include abdominal pain and vaginal bleeding. Occasionally, pain will be the only sign as the bleeding is concealed in the uterus and does not pass out of the vagina. In smaller abruptions (where a smaller portion of the placenta separates), a woman may only have bleeding without any pain. When the bleeding is large in amount, a woman may appear very ill and go into shock.