What is the primary characteristic of placental abruption?

The primary characteristic of placental abruption is the premature separation of the placenta from the uterine wall. This condition typically occurs before the delivery of the baby and can lead to significant complications for both the mother and child, including bleeding, fetal distress, and increased risk of preterm birth.

During abruption, the placenta detaches partially or completely from its implantation site before labor begins, which can compromise the blood supply to the fetus and cause maternal symptoms such as abdominal pain and uterine tenderness. Recognizing this condition is critical, as it requires prompt diagnosis and management to ensure the safety of both the mother and baby.

The other options focus on different aspects that are not central to defining placental abruption. For instance, complete placental adhesion relates to placenta accreta, and the formation of a clot within the placenta may occur due to various other placental pathologies. Delayed onset of uterine contractions can happen in other scenarios as well and is not a defining characteristic of placental abruption.