A separation of the placenta from the uterine wall, or placenta abruptio, can be difficult to identify. Diagnosis is based on a physical examination, a medical history, and a process of elimination. Testing may include:

• Fetal heart monitoring, to assess the fetus's condition and check for contractions of the uterus.
• An ultrasound test, which can detect about 50% of placental abruptions.⁵ A negative ultrasound result does not necessarily guarantee that the placenta is intact.
• A blood test for anemia. A woman with placenta abruptio can become anemic from excessive blood loss.