Which of the following best defines abruptio placenta?

Abruptio placenta, also known as placental abruption, specifically refers to the premature separation of the placenta from the uterine wall before delivery. This condition can lead to significant maternal and fetal complications, including bleeding, fetal distress, and preterm birth. It is important to recognize the signs and symptoms of placental abruption, such as sudden abdominal pain and vaginal bleeding, as prompt medical intervention may be necessary to ensure the safety of both the mother and the baby.

The other options do not accurately depict this condition. For instance, infection of the placenta pertains to chorioamnionitis, which is a separate medical condition involving infection during pregnancy. Painful uterine contractions might indicate labor or other issues but do not specifically relate to the separation of the placenta. The early removal of the placenta may imply a medical intervention that could occur after separation, but it does not define the event itself. Therefore, the separation of the placenta prior to delivery is the most accurate and encompassing definition of abruptio placenta.