INTRODUCTION

Abruptio placentae (ie, placental abruption) refers to separation of the normally located placenta after the 20th week of gestation and prior to birth.

Pathophysiology:

Bleeding into the decidua basalis leads to separation of the placenta. 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 obstetrical emergency. Severity of fetal distress correlates with the degree of placental separation. In near-complete or complete abruption, fetal death is inevitable unless an immediate cesarian delivery is performed.

  • Abruptio placentae occurs in about 1% of all pregnancies throughout the world.

 Maternal and fetal death may occur because of hemorrhage and coagulopathy. The fetal perinatal mortality rate is approximately 15%.

CLINICAL

History:

  • Patients usually present with the following symptoms:

    • Vaginal bleeding

    • Abdominal or back pain and uterine tenderness

    • Fetal distress

    • Abnormal uterine contractions (eg, hypertonic, high frequency)

    • Idiopathic premature labor 
    • Fetal death
     

Placental abruption is mainly a clinical diagnosis based on findings of vaginal bleeding, abdominal pain, uterine tenderness, uterine contractions, and fetal distress. Severe uterine pain and tenderness with mild vaginal bleeding in a patient with hypertension (HTN) indicates placental abruption.

Classification of placental abruption is based on extent of separation (ie, partial vs complete) and location of separation (ie, marginal vs central). Clinical characteristics include the following:

  • Class 0 is asymptomatic. Diagnosis is made retrospectively by finding an organized blood clot or a depressed area on a delivered placenta.

  • Class 1 is mild and represents approximately 48% of all cases. 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 is moderate and represents approximately 27% of all cases. 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 is severe and represents approximately 24% of all cases. Characteristics include the following:

    • No vaginal bleeding to heavy vaginal bleeding

    • Very painful tetanic uterus

    • Maternal shock

    • Hypofibrinogenemia (ie,

    • Coagulopathy

    • Fetal death

Causes:

  • Maternal hypertension - Most common cause of abruption, occurring in approximately 44% of all cases

  • Maternal trauma (eg, motor vehicle accidents [MVA], assaults, falls) - Causes 1.5-9.4% of all cases

  • Cigarette smoking

  • Alcohol consumption

  • Cocaine use

  • Sudden decompression of the uterus (eg, premature rupture of membranes, delivery of first twin)

  • Retroplacental fibromyoma

  • Retroplacental bleeding from needle puncture (ie, postamniocentesis)

  • Advanced maternal age

  • Idiopathic (probable abnormalities of uterine blood vessels and decidua)

  • Folic Acid deficiency.

DIFFERENTIALS

Abdominal Trauma, Blunt
Appendicitis, Acute
Disseminated Intravascular Coagulation
Ovarian Cysts
Ovarian Torsion
Placenta Previa
Pregnancy, Delivery
Pregnancy, Ectopic >
Pregnancy, Preeclampsia
Pregnancy, Trauma
Shock, Hemorrhagic
Shock, Hypovolemic
Vaginitis

 

Laboratory Studies

  • Hemoglobin

  • Hematocrit

Platelets

  • Prothrombin time/activated partial thromboplastin time

  • Fibrinogen

  • Fibrin/fibrinogen degradation products

  • D-dimer

  • Blood type

Imaging Studies:

  • Ultrasonography helps determine the location of the placenta. (Location is used to exclude previa.) Ultrasonography is not very useful in diagnosing placental abruption.

    • Retroplacental hematoma may be recognized in 2-25% of all abruptions.

    • Recognition of retroplacental hematoma depends on the degree of hematoma and on the operator's skill level.

TREATMENT

 Provide emergency care to all patients with suspected placental abruption. This care includes the following:

  • Continuous monitoring of vital signs

  • Continuous, high-flow, supplemental oxygen

  • One or 2 large-bore IV lines with normal saline (NS) or lactated Ringer (LR) solution

  • Monitor amount of vaginal bleeding

  •   Treatment of hemorrhagic shock, if needed.

  • Closely observe the patient..

  • Perform fetal monitoring.

  • Perform aggressive fluid resuscitation to maintain adequate perfusion, if needed.

  • Monitor vital signs and urine output.

  • Transfuse, if necessary. Crossmatch 4 units of packed red blood cells.

  • Perform amniotomy to decrease intrauterine pressure, extravasation of blood into the myometrium, and entry of thromboplastic substances into the circulation.

  • Immediately deliver the fetus by cesarean delivery if the mother or fetus becomes unstable.

  • Treatment of coagulopathy or disseminated intravascular coagulation (DIC) may be necessary. Some degree of coagulopathy occurs in about 30% of severe cases of placental abruption. The best treatment for DIC as a complication of placental abruption is immediate delivery..

Further Inpatient Care:

  • Labor, delivery, and postpartum care

  • Further management of the complications of abruptio placentae

Prevention:

  • Treat maternal hypertension.

  • Prevent maternal trauma/domestic violence.

  • Prevent smoking and substance abuse.

  • Diagnose placental abruption at an early stage in high-risk groups (eg, maternal hypertension, maternal trauma, association with domestic violence, smoking habit, substance abuse, advanced maternal age, premature ruptured membranes, uterine fibromyomas, amniocentesis).

  • Folic Acid supplementation from early Pregnancy.

Complications:

  • Maternal complications

    • Hemorrhagic shock

    • Coagulopathy/DIC

    • Uterine rupture

    • Renal failure

    • Ischemic necrosis of distal organs (eg, hepatic, adrenal, pituitary)

  • Fetal complications

    • Hypoxia

o        Anemia

o        Growth retardation

o        CNS anomalies

o        Fetal death

Pitfalls:

  • Some patients may not have the classic presentation of abruption, especially with posterior implantation.

  • Consider a diagnosis of placental abruption for every patient in premature labor. Carefully monitor patients to exclude or establish this diagnosis.

  • Absence of vaginal bleeding does not exclude placental abruption.

  • DIC/coagulopathy may occur even if clotting factors initially are within reference ranges. Continue to monitor clotting factors

  • Normal ultrasound findings do not exclude placental abruption.