How do you know if you have a placental abruption?

Abruption. You feel cramping abdominal pain, which can be severe, you may have vaginal bleeding also. Sometimes decreased fetal movements. So everytime you have vaginal bleeding, cramping, decreased fetal movements you should notify your doctor asap.
Contractions/bleedin. Abruption is a bleed from the placenta; a disruption of either the mother or baby's blood supply. Many causes: trauma, high blood pressure, drugs (cocaine), preterm labor, polyhydramnios. Can be very large or very small, so even US can miss a diagnosis. Symptoms: usually preterm contractions, sometimes vaginal bleed. Fetal monitoring is necessary. Wait, watch; abruption can self-heal sometimes.