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.)
View Image
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.
The primary cause of placental abruption is usually unknown, but multiple risk factors have been identified.[1, 2, 3] However, only a few events have been closely linked to this condition.
Risk factors in abruptio placentae include the following:
Maternal hypertension - Most common cause of abruption, occurring in approximately 44% of all cases
Maternal trauma (eg, motor vehicle collision [MVC], assaults, falls) - Causes 1.5-9.4% of all cases
Cigarette smoking
Alcohol consumption
Cocaine use
Short umbilical cord
Sudden decompression of the uterus (eg, premature rupture of membranes, delivery of first twin)
Retroplacental fibromyoma
Retroplacental bleeding from needle puncture (ie, postamniocentesis)
Idiopathic (probable abnormalities of uterine blood vessels and decidua)[4]
Previous placental abruption
Chorioamnionitis[5]
Prolonged rupture of membranes (24 h or longer)
Maternal age 35 years or older
Maternal age younger than 20 years
Male fetal sex
Low socioeconomic status
Elevated second trimester maternal serum alpha-fetoprotein (associated with up to a 10-fold increased risk of abruption)
Subchorionic hematoma[6]
Cigarette smoking/tobacco abuse
Cigarette smoking increases a patient's overall risk of placental abruption.[7]
A prospective cohort study showed the risk of abruption to be increased by 40% for each year of smoking prior to pregnancy.
In addition to the increased risk of abruption caused by tobacco abuse, the perinatal mortality rate of infants born to women who smoke and have an abruption is increased.[8, 9]
Cocaine (powder or crack) abuse
The hypertension and increased levels of catecholamines caused by cocaine abuse are thought to be responsible for a vasospasm in the uterine blood vessels that causes placental separation and abruption. However, this hypothesis has not been definitively proven.
The rate of abruption in patients who abuse cocaine has been reported to be approximately 13-35% and may be dose-dependent.[10]
Trauma
Abdominal trauma is a major risk factor for placental abruption.
Motor vehicle accidents often cause abdominal trauma. The lower seat belt should extend across the pelvis, not across the midabdomen, where the fetus is located.
Trauma may also be due to domestic abuse or assault, both of which are underreported.
Thrombophilia
While it was previously thought that patients who experienced early or severe abruptions were at increased risk of having a specific thrombophilia, this is no longer thought to be the case and screening of patients with an abruption is no longer recommended.
The frequency of abruptio placentae in the United States is approximately 1%, and a severe abruption leading to fetal death occurs in 0.12% of pregnancies (1:830).
Abruptio placentae also occurs in about 1% of all pregnancies throughout the world.
Race predilection
Placental abruption is more common in African American women than in white or Latin American women. However, whether this is the result of socioeconomic, genetic, or combined factors remains unclear.
Age predilection
An increased risk of placental abruption has been demonstrated in patients younger than 20 years and those older than 35 years.
If the bleeding continues, fetal and maternal distress may develop. Fetal and maternal death may occur if appropriate interventions are not undertaken.
The 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.[11]
If an abruption occurs, the risk of perinatal mortality is reported as 119 per 1,000 people in the United States, but this can depend on the extent of the abruption and the gestational age of the fetus.[12, 13] This rate is higher in patients with a significant smoking history.
Currently, placental abruption is responsible for approximately 6% of maternal deaths.
Morbidity associated with abruptio placentae
Fetal morbidity is caused by the insult of the abruption itself and by issues related to prematurity when early delivery is required to alleviate maternal or fetal distress.
Maternal morbidity may include the following:
Transfusion-related morbidity
Classic cesarean delivery with need for repeat cesarean deliveries
Hysterectomy[14]
Maternal and fetal complications include issues related to (1) cesarean delivery, (2) hemorrhage/coagulopathy, and (3) prematurity.
Cesarean delivery
Cesarean delivery is often necessary if the patient is far from her delivery date or if significant fetal compromise develops. If significant placental separation is present, the fetal heart rate tracing typically shows evidence of fetal decelerations and even persistent fetal bradycardia.
A cesarean delivery may be complicated by infection, additional hemorrhage, the need for transfusion of blood products, injury of the maternal bowel or bladder, and/or hysterectomy for uncontrollable hemorrhage. In rare cases, death occurs.
Hemorrhage/coagulopathy
Disseminated intravascular coagulation (DIC) may occur as a sequela of placental abruption. Patients with a placental abruption are at higher risk of developing a coagulopathic state than those with placenta previa. The coagulopathy must be corrected to ensure adequate hemostasis in the case of a cesarean delivery.
Prematurity
Delivery is required in cases of severe abruption or when significant fetal or maternal distress occurs, even in the setting of profound prematurity. In some cases, immediate delivery is the only option, even before the administration of corticosteroid therapy in these premature infants. All other problems and complications associated with a premature infant are also possible.
Recurrence
The risk of recurrence of abruptio placentae is reportedly 4-12%. If the patient has abruptio placentae in 2 consecutive pregnancies, the risk of recurrence rises to 25%.
If the abruption is severe and results in the death of the fetus, the risk of a recurrent abruption and fetal demise is 7%.
Maternal cardiovascular mortality
A study by Pariente et al indicated that women who have placental abruption are at increased long-term risk for cardiovascular mortality. The study examined the cardiovascular mortality rate after 653 deliveries in patients with placental abruption, with follow-up occurring over more than 10 years. Although the investigators did not find a significant connection between placental abruption and later, long-term hospitalization for cardiovascular disease, they found a 13% cardiovascular mortality rate in the women who had suffered placental abruption, compared with a 2.5% rate in women who had not.[15]
Symptoms may include vaginal bleeding, contractions, abdominal tenderness, and decreased fetal movement. Eliciting any history of trauma, such as assault, abuse, or motor vehicle accident, is important.
A quick review of the patient's prenatal course, such as a known history of placenta previa, may help lead to the correct diagnosis.[16] The patient should also be asked if she has had a placental abruption in a previous pregnancy.
Questioning the patient about cocaine abuse, hypertension, trauma, or tobacco abuse is also crucial.
Frequency of symptoms in placental abruption is as follows:
Vaginal bleeding - 80%
Abdominal or back pain and uterine tenderness - 70%
Fetal distress - 60%
Abnormal uterine contractions (eg, hypertonic, high frequency) - 35%
Idiopathic premature labor - 25%
Fetal death - 15%
Vaginal bleeding
Vaginal bleeding is present in 80% of patients diagnosed with placental abruptions.
Bleeding may be significant enough to jeopardize fetal and maternal health in a relatively short period.
Remember that 20% of abruptions are associated with a concealed hemorrhage, and the absence of vaginal bleeding does not exclude a diagnosis of abruptio placentae.
Contractions/uterine tenderness
Contractions and uterine hypertonus are part of the classic triad observed with placental abruption.
Uterine activity is a sensitive marker of abruption and, in the absence of vaginal bleeding, should suggest the possibility of an abruption, especially after some form of trauma or in a patient with multiple risk factors.
Decreased fetal movement
This may be the presenting complaint.
Decreased fetal movement may be due to fetal jeopardy or death.
The physical examination of a patient who is bleeding must be targeted at determining the origin of the hemorrhage. Simultaneously, the patient must be stabilized quickly. With placental abruption, a relatively stable patient may rapidly progress to a state of hypovolemic shock.
Do not perform a digital examination on a pregnant patient with vaginal bleeding without first ascertaining the location of the placenta. Before a pelvic examination can be safely performed, an ultrasonographic examination should be performed to exclude placenta previa.[17] If placenta previa is present, a pelvic examination, either with a speculum or with bimanual examination, may initiate profuse bleeding.
Vaginal bleeding
Bleeding may be profuse and come in "waves" as the patient's uterus contracts.
A fluid the color of port wine may be observed when the membranes are ruptured.
Contractions/uterine tenderness
Uterine contractions are a common finding with placental abruption.
Contractions progress as the abruption expands, and uterine hypertonus may be noted.
Contractions are painful and palpable.
Uterine hyperstimulation may occur with little or no break in uterine activity between contractions
Shock
Patients may present with hypovolemic shock, with or without vaginal bleeding, because a concealed hemorrhage may be present.
As with any hypovolemic condition, blood pressure drops as the pulse increases, urine output falls, and the patient progresses from an alert to an obtunded state as the condition worsens.
Absence of fetal heart sounds
This occurs when the abruption progresses to the point of fetal death.
Signs of possible fetal jeopardy
Signs of possible fetal jeopardy include the following:
Prolonged fetal bradycardia
Repetitive, late decelerations
Decreased short-term variability
Fundal height
This may increase rapidly because of an expanding intrauterine hematoma.
No laboratory studies have been shown to definitively help with the differential diagnosis of abruptio placentae; however, multiple laboratory studies may be helpful in the management of this problem.
CBC count
A complete blood cell (CBC) count can help to determine the patient's current hemodynamic status, but findings are not reliable for estimating acute blood loss.
In an acute hemorrhage, the fall in hematocrit value lags several hours behind the bleeding and may be falsely decreased by the administration of crystalloid fluids during resuscitation.
Fibrinogen study
Pregnancy is associated with hyperfibrinogenemia; therefore, modestly depressed fibrinogen levels may represent significant coagulopathy. A fibrinogen level of less than 200 mg/dL suggests that the patient has a severe abruption.
The goal should be to keep the fibrinogen level above 100 mg/dL, which can be accomplished via transfusion of fresh frozen plasma or cryoprecipitate, as necessary.
Prothrombin time (PT)/activated partial thromboplastin time (aPTT)
Some form of disseminated intravascular coagulation (DIC) is present in up to 20% of patients with severe abruptions.
Because many of these patients require cesarean delivery, knowing a patient's coagulation status is imperative.
Blood urea nitrogen (BUN)/creatinine study
The hypovolemic condition brought on by a significant abruption also affects renal function.
The condition usually self-corrects without significant residual dysfunction, if fluid resuscitation is timely and adequate.
Blood and Rh types
The patient should have her blood typed and at least 2 units of packed red blood cells crossmatched in the event she requires a transfusion.
The blood Rh type is important to determine, because patients who are Rh-negative require Rh immune globulin to prevent isoimmunization, which could affect future pregnancies.
Kleihauer-Betke test
Findings help to detect fetal red blood cells in the maternal circulation.
If the abruption is significant, inadvertent transfusion of fetal blood into the maternal circulation may occur. In women who are Rh-negative, this fetal-to-maternal transfusion may lead to isoimmunization of the mother to Rh factor. Kleihauer-Betke test findings help to determine the volume of fetal blood transfused into the maternal circulation.
All patients who are D-negative should receive Rho (D) immune globulin (RhoGAM) after significant trauma. Kleihauer-Betke test findings may help to determine the appropriate dosage of Rho (D) immune globulin in cases of significant fetal-maternal hemorrhage.
Ultrasonography is a readily available and important imaging modality for assessing bleeding in pregnancy.
The quality and sensitivity of ultrasonography in detecting placental abruptions has improved significantly; however, it is not a sensitive modality for this purpose—findings are positive in only 25% of cases confirmed at delivery, and the negative predictive value is low at around 50%.
In addition, there does not appear to be any clinical difference in presentation between women who have an abruption seen on ultrasonography and those who do not.
Ultrasonographic studies do help to quickly diagnose placenta previa as the etiology of bleeding, if present.[18]
Placental abruption shows as a retroplacental clot on an ultrasonographic image, but not all abruptions are ultrasonographically detectable.
In the acute phase, a hemorrhage is generally hyperechoic, or even isoechoic, compared with the placenta; a hemorrhage does not become hypoechoic for nearly a week.
Ultrasonography can help to exclude other causes of third-trimester bleeding. Possible findings consistent with an abruption include (1) retroplacental clot (ie, hyperechoic to isoechoic in the acute phase, changing to hypoechoic within a wk), (2) concealed hemorrhage, or (3) expanding hemorrhage.
External fetal monitors often reveal fetal distress, as evidenced by late decelerations, fetal bradycardia, or decreased beat-to-beat variability.
An increase in the uterine resting tone may also be noticed, along with frequent contractions that may progress to uterine hyperstimulation, as seen in the fetal tracing below.
View Image
Fetal tracing with placental abruption. Decreased short-term variability, increased baseline uterine tone, uterine hyperstimulation, and worsening var....
Any procedures that may be required (ie, continuous monitoring of the fetal heart rate tracing, vaginal delivery, cesarean delivery) will be dictated by the gestational age and overall status of the fetus. This is discussed in more detail below.
After delivery of the placenta, a retroplacental clot may be noted. Another possible finding involves extravasation of blood into the myometrium, which produces a purple discoloration of the uterine serosa. This phenomenon is known as a Couvelaire uterus.
A study that included the data from 35,307 women and 250 cases of abruption reported abnormal pregnancy-associated plasma protein A, maternal serum alpha-fetoprotein, and inhibin-A analytes were associated with increased risk of abruption. The study also found that the risk of abruption in women with all three serum analytes increased eight times (95% CI 2.3-34.3).[19]
Inpatient admission for testing and possible delivery is required if abruptio placentae is considered likely.
See Emergent Management of Abruptio Placentae for complete information on this topic.
Transfer considerations
Transfer of the patient to an intensive care unit (ICU) may be necessary, before or after delivery, if the patient is hemodynamically unstable, such as if shock develops, and requires invasive central monitoring or if operative complications are encountered.
Transfer to a facility with a neonatal ICU is needed if the fetus is preterm and appropriate facilities are not available. This should be accomplished after delivery if delivery is required to stabilize the mother.
Begin continuous external fetal monitoring for the fetal heart rate and contractions.
Obtain intravenous access using 2 large-bore intravenous lines.
Institute crystalloid fluid resuscitation for the patient.
Type and crossmatch blood.
Begin a transfusion if the patient is hemodynamically unstable after fluid resuscitation.
Correct coagulopathy, if present.
Administer Rh immune globulin if the patient is Rh-negative.
Begin course of corticosteroids for fetal lung maturity (if the patient is less than 37 weeks gestation and they have not been previously given during pregnancy).[20]
Cesarean delivery is often necessary for fetal and maternal stabilization.
While cesarean delivery facilitates rapid delivery and direct access to the uterus and its vasculature, it can be complicated by the patient's coagulation status. Because of this, a vertical skin incision, which has been associated with less blood loss, is often used when the patient appears to have DIC.
The type of uterine incision is dictated by the gestational age of the fetus, with a vertical or classic uterine incision often being necessary in the preterm patient.
If hemorrhage cannot be controlled after delivery, a cesarean hysterectomy may be required to save the patient's life.
Before proceeding to hysterectomy, other procedures, including correction of coagulopathy, ligation of the uterine artery, administration of uterotonics (if atony is present), packing of the uterus, and other techniques to control hemorrhage, may be attempted.
The patient should be restricted to nothing by mouth (NPO) if emergent delivery is a possibility.
Activity restrictions
Preterm patients diagnosed with a chronic abruption may be started on a modified bedrest regimen and monitored closely for any signs of maternal or fetal distress that could necessitate delivery. Again, consultation with maternal-fetal medicine (MFM) specialists is advised for conservative management of abruptio placentae.
Elimination of correctable risk factors can decrease the risk of recurrence in subsequent pregnancies.
Two of the most notable correctable factors are smoking and cocaine abuse. Education about the risks of these behaviors and about cessation or rehabilitation programs may help to prevent future abruptions.
If a patient has been abused, preventing further abuse is an important consideration.
Because of the potential association with thrombophilias with abruptio placentae, a patient found to have a thrombophilia who had a severe or early abruption, especially with death of the fetus, is usually treated with heparin anticoagulation therapy during the following pregnancy and for 6 weeks' postpartum, although, at present, little evidence has demonstrated that this measure decreases the risk of recurrence.
A maternal-fetal medicine (MFM) specialist should be consulted if a mild abruption is diagnosed or the diagnosis is questionable. In the case of a preterm fetus in which tocolysis is considered likely, consulting an MFM specialist may be prudent.
Pediatricians or neonatal intensive care specialists should be consulted if the fetus is considered viable, usually at 24 weeks' gestation, and delivery is anticipated.
Tocolysis is considered controversial in the management of placental abruption and is considered only in patients (1) who are hemodynamically stable, (2) in whom no evidence of fetal jeopardy exists, and (3) in whom a preterm fetus may benefit from corticosteroids or delay of delivery.
Even in patients meeting these criteria, consultation with an MFM specialist is important. Tocolysis must be undertaken with caution, because maternal or fetal distress can develop rapidly. In general, either magnesium sulfate or nifedipine (but not both) is used for tocolysis and beta-sympathomimetic agents are avoided, as the latter may cause significant undesirable cardiovascular effects, such as tachycardia, which may mask clinical signs of blood loss in these patients.
Clinical Context:
Nifedipine is a calcium channel blocker. The theory behind its use as a tocolytic is that by blocking an influx of calcium into uterine muscle cells, it will decrease contractions, which are dependent on calcium.
Tocolytics may allow for the effective administration of glucocorticoids to the preterm fetus to accelerate fetal lung maturation. In chronic abruption, these drugs may also help to delay delivery to a gestational age when complications of prematurity are less severe.
Corticosteroids are given when preterm delivery (less than 37 weeks) is expected. They are associated with a decreased risk of neonatal respiratory distress, necrotizing enterocolitis, and intracranial hemorrhage. The two most used medications are betamethasone and dexamethasone. While they should be considered if the patient is preterm with an abruption, delivery should not be delayed for their administration.
How is abruptio placentae defined?What are the possible complications of abruptio placentae?How is abruptio placentae classified?What causes abruptio placentae?What are the risk factors for abruptio placentae?What is the role of cigarette smoking in the etiology of abruptio placentae?What is the role of cocaine use in the etiology of abruptio placentae?What is the role of trauma in the etiology of abruptio placentae?What is the role of thrombophilia in the etiology of abruptio placentae?What is the prevalence of abruptio placentae in the US?What is the global prevalence of abruptio placentae?What are the racial predilections of abruptio placentae?Which age groups are at highest risk for abruptio placentae?What is the prognosis of abruptio placentae?What is the morbidity associated with abruptio placentae?How does cesarean delivery affect the prognosis of abruptio placentae?What are the possible coagulation complications of abruptio placentae?What is the risk of premature delivery in pregnancies complicated by abruptio placentae?What is the risk of recurrence of abruptio placentae?What is the maternal mortality risk of abruptio placentae?What is included in patient education about abruptio placentae?Which clinical history findings are characteristic of abruptio placentae?What is the prevalence of vaginal bleeding in abruptio placentae?How is uterine activity characterized in abruptio placentae?What caused decreased fetal movement in abruptio placentae?How is the physical exam to evaluate abruptio placentae performed?How is vaginal bleeding characterized in abruptio placentae?How are uterine contractions characterized in abruptio placentae?What are the signs and symptoms of shock in abruptio placentae?What are the signs of fetal death in abruptio placentae?What are the signs of fetal distress in abruptio placentae?Which fundal height findings are characteristic of abruptio placentae?Which conditions are included in the differential diagnoses of abruptio placentae?What are the differential diagnoses for Abruptio Placentae?What is the role of lab tests in the workup of abruptio placentae?What is the role of CBC count in the workup of abruptio placentae?What is the role of a fibrinogen study in the workup of abruptio placentae?What is the role of coagulation studies in the workup of abruptio placentae?What is the role of BUN studies in the workup of abruptio placentae?What is the role of a blood typing in the workup of abruptio placentae?What is the role of a Kleihauer-Betke test in the workup of abruptio placentae?What is the role of ultrasonography in the workup of abruptio placentae?What is the role of fetal monitoring in in the workup of abruptio placentae?What is the role of a biophysical profile (BPP) in the workup of abruptio placentae?Which histologic findings are characteristic of abruptio placentae?What is the role of serum analytes in the workup of abruptio placentae?When is inpatient care indicated for the treatment of abruptio placentae?When is patient transfer required for the treatment of abruptio placentae?What is the initial treatment of abruptio placentae?When is vaginal delivery indicated for abruptio placentae?What is the role of cesarean delivery in the treatment of abruptio placentae?Which dietary modifications are used in the treatment of abruptio placentae?Which activity modifications are used in the treatment of abruptio placentae?Which medications are used in the treatment of abruptio placentae?How is abruptio placentae prevented?Which specialist consultations are beneficial to patients with abruptio placentae?What is the role of medications in the treatment of abruptio placentae?Which medications in the drug class Corticosteroids are used in the treatment of Abruptio Placentae?Which medications in the drug class Tocolytics are used in the treatment of Abruptio Placentae?
Shad H Deering, MD, Medical Director, Andersen Simulation Center, Madigan Army Medical Center
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
John G Pierce, Jr, MD, Associate Professor, Departments of Obstetrics/Gynecology and Internal Medicine, Medical College of Virginia at Virginia Commonwealth University
Disclosure: Nothing to disclose.
Chief Editor
Carl V Smith, MD, The Distinguished Chris J and Marie A Olson Chair of Obstetrics and Gynecology, Professor, Department of Obstetrics and Gynecology, Senior Associate Dean for Clinical Affairs, University of Nebraska Medical Center
Disclosure: Nothing to disclose.
Additional Contributors
Bruce A Meyer, MD, MBA, Executive Vice President for Health System Affairs, Executive Director, Faculty Practice Plan, Professor, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical School
Disclosure: Nothing to disclose.
Acknowledgements
The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous author Andrew Satin, MD, to the development and writing of the source article.
ACOG Committee Opinion. Antenatal Corticosteroid Therapy for Fetal Maturation. ACOG. Available at https://www.acog.org/-/media/Committee-Opinions/Committee-on-Obstetric-Practice/co677.pdf?dmc=1&ts=20160922T2345049022. Number 677, October 2016; Accessed: November 23, 2016.
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