Practice Essentials
Abruptio placentae is defined as the premature separation of the placenta from the uterus. Patients with abruptio placentae, also called placental abruption, typically present with bleeding, uterine contractions, and fetal distress. A significant cause of third-trimester bleeding associated with fetal and maternal morbidity and mortality, placental abruption must be considered whenever bleeding is encountered in the second half of pregnancy.{ref121-INVALID REFERENCE} Placental abruption is demonstrated in the image below. (See Clinical.)
Placental abruption seen after delivery.
Complications
Hemorrhage into the decidua basalis occurs as the placenta separates from the uterus. Vaginal bleeding usually follows, although the presence of a concealed hemorrhage in which the blood pools behind the placenta is possible. (See Workup.)
Hematoma formation further separates the placenta from the uterine wall, causing compression of these structures and compromise of blood supply to the fetus. Retroplacental blood may penetrate through the thickness of the uterine wall into the peritoneal cavity, a phenomenon known as Couvelaire uterus. The myometrium in this area becomes weakened and may rupture with increased intrauterine pressure during contractions. A myometrium rupture immediately leads to a life-threatening obstetric emergency. (See Treatment.)
Classification of placental abruption
Classification of placental abruption is based on extent of separation (ie, partial vs complete) and location of separation (ie, marginal vs central). (See Clinical.) Clinical classification is as follows:
Class 0 – Asymptomatic
Class 1 – Mild (represents approximately 48% of all cases)
Class 2 – Moderate (represents approximately 27% of all cases)
Class 3 – Severe (represents approximately 24% of all cases)
A diagnosis of class 0 is made retrospectively by finding an organized blood clot or a depressed area on a delivered placenta.
Class 1 characteristics include the following:
No vaginal bleeding to mild vaginal bleeding
Slightly tender uterus
Normal maternal BP and heart rate
No coagulopathy
No fetal distress
Class 2 characteristics include the following:
No vaginal bleeding to moderate vaginal bleeding
Moderate to severe uterine tenderness with possible tetanic contractions
Maternal tachycardia with orthostatic changes in BP and heart rate
Fetal distress
Hypofibrinogenemia (ie, 50-250 mg/dL)
Class 3 characteristics include the following:
No vaginal bleeding to heavy vaginal bleeding
Very painful tetanic uterus
Maternal shock
Hypofibrinogenemia (ie, < 150 mg/dL)
Coagulopathy
Fetal death
Go to Emergent Management of Abruptio Placentae for complete information on this topic.