Background: Abruptio placentae
is defined as premature separation of the placenta from the uterus. Clinically
it most often presents with bleeding, uterine contractions, and fetal distress.
It is a significant cause of third trimester bleeding and is associated with
both fetal and maternal morbidity and mortality. It must be entertained as a
diagnosis anytime third trimester bleeding is encountered.
Pathophysiology: As the placenta separates from the uterus,
hemorrhage ensues into the decidua basalis. Vaginal bleeding usually follows,
although it is possible to have a concealed hemorrhage where the blood pools
behind the placenta.
If the bleeding continues, fetal and maternal distress may develop with fetal
and then maternal death if appropriate interventions do not occur. The primary
cause of placental abruption is unknown, but there are multiple risk factors
that have been identified.
- In the US: Frequency of abruptio placentae in the US is
Mortality/Morbidity: Maternal or fetal
The overall fetal mortality rate for placental abruption is between 20-40%,
depending on the extent of the abruption. It is higher in patients with a
significant smoking history. Fetal morbidity is caused by the insult of the
abruption itself, as well as issues of prematurity.
Placental abruption is currently responsible for approximately 6% of maternal
deaths. Maternal complications include:
- Cesarean delivery: Cesarean delivery is often necessary if the patient is
remote from delivery or if there is significant fetal compromise. Typically,
if there is significant placental separation, the fetal heart tracing will
show evidence of fetal decelerations and even persistent fetal bradycardia.
- Hemorrhage/coagulopathy: Disseminated intravascular coagulation may occur
as a sequela to placental abruption. Placental abruption is more at risk for
developing a coagulopathic state than placental previa. The coagulopathy must
be corrected to ensure adequate hemostasis in the case of a cesarean delivery.
- Prematurity: Delivery is the most important step in cases of severe
abruption, even in the setting of profound prematurity. In some cases,
immediate delivery is the only option even before administration of
corticosteroid therapy in these premature infants. All other problems and
complications associated with a premature infant are possible as well.
Race: Placental abruption is more common in African American
women than in either Caucasian or Latin American women. However, it is unclear
as to whether this is the result of socioeconomic, genetic, or a combination of
Sex: This is a disease observed only in pregnancy.
Age: An increased risk of placental abruption has been
demonstrated in patients younger than 20 years or older than 35 years.
History: Symptoms may include
vaginal bleeding, contractions, abdominal tenderness, and decreased fetal
movement. It is important to elicit any history of trauma, such as assault,
abuse, or a motor vehicle accident. A quick review of the patient's prenatal
course, such as a known history of a placenta previa, may help lead you to the
correct diagnosis. Questioning the patient about symptoms of cocaine use, a
history of hypertension or tobacco abuse is also important.
- Vaginal bleeding is present in 80% of patients diagnosed with placental
- Bleeding may be significant enough to cause both fetal and maternal
jeopardy in a relatively short period of time.
- It is important to remember that 20% of abruptions can have a concealed
hemorrhage and that the absence of vaginal bleeding does not rule out
abruptio placentae as the diagnosis.
- Contractions/uterine tenderness
- Contractions or uterine hypertonus are part of the classic triad seen
with placental abruption.
- Uterine activity is a sensitive marker of abruption, and in the absence
of vaginal bleeding, should raise the suspicion of an abruption, especially
following some form of trauma, or in a patient with multiple risk factors.
- This may be the presenting complaint.
- Decreased fetal movement may be due to fetal jeopardy or death.
Physical: The physical examination for a patient who is
bleeding is targeted at determining the origin of the hemorrhage. At the same
time, it is imperative that the patient be stabilized quickly. With placental
abruption the relatively stable patient may progress quickly to a state of
- A fluid the color of port wine may be observed when the membranes are
- Contractions/uterine tenderness
- Uterine contractions are a common finding with placental abruption.
- Contractions progress as the abruption progresses, and uterine
hypertonus may be noted.
- Contractions are painful and palpable.
- Patients may present with hypovolemic shock, with or without vaginal
bleeding, as 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 finding occurs when the abruption has
progressed to the point that the fetus has expired.
- Fetal jeopardy signs may include the following:
- Prolonged fetal bradycardia
- Repetitive late decelerations
- Decreased short-term variability
- Fundal height may increase rapidly, due to an expanding intrauterine
- NOTE: Do not perform a digital examination on a pregnant patient
with bleeding without first ascertaining the location of the placenta. A
placenta previa first needs to be ruled out by ultrasound before a pelvic
examination can be safely performed. If there is a placenta previa present, a
pelvic examination either with a speculum or with a bimanual examination may
initiate profuse bleeding.
Causes: While there are multiple risk factors for abruptio
placentae, there are only a few events that have been closely linked to this
- Cigarette smoking
- Cocaine (powder or crack) abuse
Other notable risk factors include:
- Prolonged rupture of membranes (24 hours or more)
- Maternal age of 35 and over
- Male fetal gender
- Low socioeconomic status
- Previous abruption
- Cigarette smoking/tobacco abuse
- Cigarette smoking increases a patient's overall risk of placental
- 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 in infants born to women who smoke and have an
abruption is increased as well.
- The hypertension and increased levels of catecholamines caused by
cocaine abuse is thought 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 incidence of abruption in patients abusing cocaine has been reported
to be about 13 to 35%, and may be dose-dependent.
- Abdominal trauma is a major risk factor for placental abruption.
- Trauma may take the form of a motor vehicle accident. The lower seat
belt should lie across the pelvis, not across the mid abdomen where the
pregnancy is located.
- Trauma also may be due to domestic abuse or assault, both of which are
Other Problems to be Considered:
Labor with bloody show
- No laboratory studies have been shown to definitively help with the
differential diagnosis of abruptio placentae, but there are multiple labs that
may be helpful in the management of this problem.
- Complete blood count (CBC)
- A CBC can help to determine the patient's current hemodynamic status but
is not that reliable in estimating acute blood loss.
- In an acute hemorrhage the fall in hematocrit lags several hours behind,
and may also be falsely decreased by the administration of crystalloid
fluids during the resuscitation.
- Pregnancy, by itself, is associated with hyperfibrinogenemia. Hence,
modestly depressed fibrinogen levels may suggest significant coagulopathy.
- The goal should be to keep the level above 100 mg/dL with transfusion of
fresh frozen plasma or cryoprecipitate, as necessary, to accomplish this.
- Some form of DIC (disseminated intravascular coagulation) is present in
as many as 20% of severe abruptions.
- As many of these patients may require a cesarean section for delivery,
it is imperative to know the patient's coagulation status.
- The hypovolemic condition brought on by a significant abruption also
impacts on renal function.
- The condition usually corrects itself without significant residual
dysfunction, provided fluid resuscitation is timely and adequate.
- This detects fetal red blood cells in the maternal circulation.
- If the abruption is significant, there may be inadvertent transfusion of
fetal blood into the maternal circulation. In women who are Rh-negative,
this fetal-to-maternal transfusion may lead to isoimmunization of the mother
to Rh factor. A Kleihauer-Betke is helpful in determining the volume of
fetal blood transfused into the maternal circulation.
- All patients who are D-negative should receive anti-D immunoglobulin (RhoGam)
after significant trauma. The Kleihauer-Betke test may help determine the
appropriate dosage of RhoGam in cases of large feto-maternal hemorrhage.
- Ultrasound is a readily available and important imaging modality for
bleeding in pregnancy.
- The quality and sensitivity of ultrasound to detect placental abruptions
has improved significantly.
- Initially, fewer than 2% were diagnosed by ultrasound, but now more than
50% of patients with confirmed placental abruptions are identified.
- Ultrasound quickly helps to diagnose placenta previa as the etiology of
bleeding if it is present.
- Placental abruption presents with retroplacental clot on the ultrasound.
As a caveat, not all abruptions are sonographically detectable.
- In the acute phase, the hemorrhage is generally hyperechoic or even
isoechoic when compared with the placenta and does not become hypoechoic for
nearly a week.
- Monitoring the fetus with external monitors often demonstrates fetal
jeopardy, as evidenced by late decelerations or fetal bradycardia.
- An increase in the uterine resting tone also may be noticed, along with
- A biophysical profile (BPP) can be used to evaluate patients with
chronic abruptions who are being conservatively managed.
- Ultrasound will help in ruling out other causes of third trimester
bleeding. Possible findings consistent with an abruption include the
- Retroplacental clot (hyperechoic to isoechoic in the acute phase,
changing to hypoechoic within a week)
Histologic Findings: After delivery of the placenta, a
retroplacental clot may be seen. Another possible finding involves extravasation
of blood into the myometrium, which produces a purple discoloration of the
uterine serosa that is known as a Couvelaire uterus.
Medical Care: Inpatient admission
is required if abruptio placentae is suspected.
- Procedures are as follows:
- Obtain IV access with 2 large bore IVs.
- Crystalloid fluid resuscitation of the patient.
- Type and crossmatch for blood.
- Transfuse patient if hemodynamically unstable after fluid resuscitation.
- Correct coagulopathy if present.
- This is the preferred method of delivery for a fetus that has died
secondary to placental abruption.
- It is dependent on the mother remaining hemodynamically stable.
- Delivery is usually rapid in these patients, secondary to the increased
uterine tone and contractions that occur.
- Delivery by cesarean section is often necessary for both fetal and
- While this allows for rapid delivery and direct access to the uterus and
its vasculature, it can be complicated by the patient's coagulation status.
- The type of uterine incision is dictated by the gestational age of the
fetus, with a vertical or classical 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 life of the patient.
- Before proceeding to hysterectomy other procedures, which include
correction of coagulopathy, uterine artery ligation, administration of
uterotonics if atony is present, and uterine packing, may be attempted.
- Maternal fetal medicine (MFM)
- If a mild abruption is diagnosed or there is a question about the
diagnosis, a maternal fetal medicine (MFM) specialist should be consulted.
- In the case of a preterm fetus in whom tocolysis is considered, it is
also prudent to consult a MFM specialist.
- Intensive care unit (ICU): If the patient is hemodynamically unstable,
either before or after delivery, invasive monitoring may be required in the
Diet: The patient should be made NPO if emergent delivery is
Activity: Patients who are diagnosed with a chronic
abruption and are preterm may be placed on modified bedrest and monitored
closely for any signs of maternal or fetal distress, which could necessitate
delivery. Again, consultation with MFM is advised for conservative management of
Tocolysis is considered controversial in the
management of placental abruption and is only considered 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
Even in patients with these criteria, consultation with a maternal fetal
medicine (MFM) specialist is important. Tocolysis must be undertaken with
caution as maternal or fetal distress can develop rapidly. In general, magnesium
sulfate is used for tocolysis rather than beta-sympathomimetic agents. The
latter has significant undesirable cardiovascular side effects in these
Drug Category: Tocolytics -- Tocolytics may
allow for effective administration of glucocorticoids to the preterm fetus to
accelerate fetal lung maturation. In a chronic abruption, it may also allow for
delay of delivery to a gestational age when complications of prematurity are
|Magnesium Sulfate -- DOC
for tocolysis in patients with placental abruption.
||4-6gm IV bolus over 20 min
2-4 gm/h maintenance rate, titrated as needed to suppress contractions
hypersensitivity; hypocalcemia; myasthenia gravis, renal failure
||Concurrent use with
nifedipine may cause hypotension and neuromuscular blockade; may increase
neuromuscular blockade seen with aminoglycosides and potentiate
neuromuscular blockade produced by tubocurarine, vecuronium, and
succinylcholine; may increase CNS effects and toxicity of CNS depressants,
betamethasone, and cardiotoxicity of ritodrine
||B - Usually safe but
benefits must outweigh the risks.
||Adverse effects include
flushing, blurry vision, headaches, and nausea; more serious adverse
effects, seen only at toxic levels, include pulmonary edema, respiratory
depression, cardiac arrest, maternal tetany, profound hypotension
to reverse effects of magnesium sulfate (calcium gluconate 1 g slow IV push
may be given)
Further Inpatient Care:
- Admit for testing and possible delivery.
In/Out Patient Meds:
- Stool softeners if the patient is hemodynamically stable and is kept as an
inpatient for monitoring
- ICU transfer may be necessary before or after delivery if shock develops
that requires invasive central monitoring or operative complications are
- Transfer to a facility with a neonatal intensive care unit (NICU) 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.
- Elimination of correctable risk factors can decrease the risk of
recurrence in subsequent pregnancies.
- Two of the most notable factors that can be corrected are smoking and
cocaine abuse. Education about the risks of these behaviors as well as
cessation or rehabilitation programs may help prevent future abruptions.
- If the patient was the victim of abuse, then preventing further abuse from
occurring is an important consideration.
- Transfusion-related morbidity
- Classical cesarean delivery with need for repeat cesarean deliveries.
- The risk of recurrence of abruptio placentae is between 4-12%.
- It is important to educate patients about reversible risk factors,
especially smoking, for any further pregnancies.
- Questions regarding possible trauma from abuse should also be asked.
- Failure to recognize signs and symptoms of abruptio placentae
- Failure to intervene in a timely manner
- As with any case in obstetrics there is always the possibility for
litigation. Controversial decisions made regarding placental abruption,
especially when tocolysis is considered, should be made in consultation with a
maternal fetal medicine (MFM) specialist.
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