Description

Bleeding at the decidua-placental interface. The diagnosis is typically reserved for pregnancies after 20 weeks.

Epidemiology

Incidence

• The overall prevalence rate of abruption in United States is 9.6/1,000, of which 2/3 of cases were classified as being severe (6.5/1,000).
• 80% of cases occur prior to onset of delivery.
• 40–60% occur before 37 weeks of gestation; 14% occur before 32 weeks.
• Risk of placental abruption is higher if:
  • History placental abruption in first pregnancy
  • Hypertensive disorders in the index pregnancy
  • At extremes of age in the reproductive window

Etiology and Pathophysiology

• Acute
  • Etiology of bleeding at the decidua basalis in most cases remains elusive.
  • May be caused by sudden mechanical events, such as blunt abdominal trauma or rapid uterine decompression when rupture of gestational membranes occurs, especially with polyhydramnios
  • Acute hypertension due to vasospasm or secondary to cocaine use
  • Uterine abnormalities: bicornuate uterus, uterine synechiae, leiomyomas, prior hysterotomy
• Chronic (majority of cases)
  • Occurs in chronic hypertensive disorders and associated with fetal growth restriction
  • Early bleeding in pregnancy releases thrombin and initiates chronic inflammatory pathophysiology.
  • Smoking
• Abruption is a shared final clinical outcome of diverse clinical pathways.

Genetics

• In context of the condition’s multifactorial etiology, a genetic etiology is possible for some cases. Larger case-control studies that include gene–gene and gene–environment interactions may elucidate the genetics of placental abruption.
• Placental growth is primarily under control of paternally inherited fetal genes.

Risk Factors

• Prior placental abruption increases risk by 15- to 20-fold.
• Increasing maternal age and parity
• Maternal smoking habit: dose–response relationship
• Cocaine use and abuse
• Hypertensive disorders (chronic hypertension, preeclampsia, eclampsia)
• Uterine anomalies
• Multiple-gestation pregnancies
• 1st- or 2nd-trimester bleeding
• Preterm rupture of membranes
• Polyhydramnios
• Severe small-for-gestational-age birth
• Blunt trauma/motor vehicle accident
• Chorioamnionitis
• Male infant

General Prevention

Behavioral modifications to ameliorate abruption risk:

• Smoking cessation
• Cease cocaine abuse.
• Use seat belts.

Commonly Associated Conditions

• Prenatal risks
  • Preeclampsia and other forms of hypertension in pregnancy
  • Uteroplacental insufficiency
  • Rupture of membranes
• Postnatal risks
  • Postpartum hemorrhage
  • Disseminated intravascular coagulation (DIC)
  • Maternal anemia

History

• May present with classic triad of vaginal bleeding, contractions, and abdominal pain or with complaints of discomfort or pain between contractions or contractions observed to be frequent or tetanic contraction (contractions lasting >60 seconds)
• May present in active labor or with rupture of membranes
• Back pain (especially for posterior placenta)
• Ask about recent trauma (accidental or physical abuse), cocaine or tobacco use, early trimester bleeding, and abruption in prior pregnancy.

Physical Exam

• Vital signs: tachycardia, hypotension (a late sign)
• Uterine tenderness and uterine contractions
• Vaginal bleeding (not always present i.e., concealed abruption). One possible finding occurs when symphyseal-fundal height may exceed the expected size (acutely greater than dates or previous measurement) and maternal vitals are compromised disproportionate to vaginal bleeding.
• Fetal distress or demise
• Preterm labor
• Fetal compromise evident on FHR strip pattern

Differential Diagnosis

• Placenta previa or vasa previa (1)
• Uterine rupture
• Bloody show associated with labor
• Cervical and vaginal infections (e.g., chlamydia or gonorrhea with bloody, friable cervix)
• Other painful abdominal conditions (e.g., appendicitis, pyelonephritis)
• Fibroid degeneration
• Ovarian pathology: torsed ovary, ruptured cyst

Diagnostic Tests & Interpretation

Initial Tests (lab, imaging)

• Blood type, Rh, cross-match for possible transfusion
• CBC with platelet count
• Fibrinogen levels have the best correlation with bleeding (2).
• Prothrombin time (PT)/partial thromboplastin time (PTT)
• Bedside maternal clot test: Red-top tube of maternal blood with poor or nonclotting blood after 7 to 10 minutes indicates coagulopathy.
• Fetal–maternal hemorrhage test (e.g., Kleihauer-Betke test); >30 mL fetal blood indicative of large fetal blood loss: 300-μg dose of RhoGAM will cover up to 30 mL whole fetal blood in maternal circulation.
• Ultrasound has low sensitivity and is only helpful in cases of a large abruption.
• Abnormalities of maternal serum aneuploidy analytes (AFP, hCG, PAPP-A, estriol) increase abruption risk by 10-fold.

Follow-Up Tests & Special Considerations

• DIC can result from a large abruption. Best to stabilize patient without waiting for DIC labs. This is typically a clinical diagnosis.
• Can send PT/PTT, fibrinogen levels at clinician discretion when stable or following resolution of DIC:
  • Fibrinogen levels climb to 350 to 550 mg/dL in 3rd trimester and must fall to 100 to 150 mg/dL before PTT will rise.
  • Fibrin split or degradation products are elevated in pregnancy and are not specific in assessing DIC.
• Ultrasound: Appearance or abnormality depends on size and location of the bleed (3).
  • With acute bleed that is overt, nothing may be seen as no persistent retroplacental accumulation.
  • Will fail to detect at least 50% of abruptions
  • Retroplacental clot is diagnostic of abruption.
    • If incidental abruption is found in a patient at term, delivery is reasonable.
    • A preterm patient with an incidental abruption may be managed conservatively if stable.

Diagnostic Procedures/Other

• External tocometer often shows elevated baseline pressure and frequent low-amplitude contractions.
• External fetal monitoring may show recurrent late decelerations, variable decelerations, sinusoidal fetal heart tracing, bradycardia, or decreased variability—all indicative of fetal stress.

Test Interpretation

• Placental examination after delivery may show a retroplacental clot, pathologic signs of early separation/inflammation.
• Normocytic normochromic anemia with acute bleeding
• Elevated PT/PTT, fibrinogen levels <100 to 150 mg/dL (1.0 to 1.5 g/L), platelets 20,000 to 50,000/μL if DIC is active
• Positive Kleihauer-Betke reaction if fetal–maternal transfusion has occurred
• Positive antibody if RhoD isosensitization has occurred
• Placental abruption is a clinical diagnosis.

Medication

First Line

• Tocolytics are generally contraindicated in presence of abruption.
  • Inpatient tocolytics such as nifedipine may be used in nonsevere abruption before 34 weeks (generally to administer and complete 48-hour window antenatal corticosteroids).
• RhoD immunoglobulin for RhoD-negative mother if undelivered or indicated after delivery if Kleihauer-Betke is positive
• Fluid resuscitation as required for signs of shock as part of a comprehensive care plan

Second Line

• Transfuse packed red blood cells (pRBCs) or other factors to stabilize patient as needed.
• Steroids for fetal lung maturation, if fetus is viable and <34 weeks’ gestational age
• Magnesium for 12 hours for CP prophylaxis should be considered in any patient <32 weeks’ gestational age.

Issues For Referral

Refer to tertiary care center after maternal stabilization, if preterm gestation and assessment of stability based on:

• Satisfactory and reassuring fetal heart rate monitoring strip
• Absence of concern for ongoing bleeding
• Absence of concern for expanding concealed placental abruption

Surgery/Other Procedures

• For gestations postfetal viability, cesarean delivery is indicated if maternal and fetal deterioration is perceived to be inevitable based on the progressive nature of placental abruption and labor is remote from vaginal delivery.
• Operative delivery for nonreassuring fetal heart tracing once maternal stability achieved, as abruptions can expand in a concealed manner
• Abruption-associated DIC deserves prompt hemostatic resuscitation while definitive treatment concluded with delivery and control of subsequent placental and/or surgical site bleeding.

Admission, Inpatient, and Nursing Considerations

Patients with suspected placental abruption should be admitted for workup until deemed clinically stable and ready for discharge/outpatient follow-up or delivered for medical indication.

• History and physical exam with medical history, allergies, prior ultrasounds, and time of last meal
• Management depends on presentation, gestational age, and degree of maternal and fetal compromise:
  • Delivery for severe abruption at any gestational age or nonsevere abruption >36 weeks
  • Minor abruptions (i.e., maternal status stable, fetal status reassuring, normal laboratory tests, no active vaginal bleeding) may be managed conservatively up to 36 to 37 weeks, but the risk of developing a recurrent severe abruption is high.
• In trauma, monitor in the inpatient setting for at least 4 hours for evidence of fetal insult, abruption, or fetal–maternal transfusion. If contractions or preterm labor occurs, patient should be monitored for at least 24 hours. Risk factors for contractions with trauma include the following:
  • Gestational age >35 weeks
  • Assaults and pedestrian/vehicular collisions, even without direct abdominal trauma
  • Ejections from vehicle or lack of seat belt restraint
• Early aggressive restoration of maternal physiology to protect fetus and maternal organs from hypoperfusion/DIC
• Delivery is the only definitive treatment. Expectant management occurs only for fetal immaturity that may benefit from extension of gestation, as long as this can be safely accomplished.
• Inpatient care with external fetal and labor monitoring, if fetus is viable
• Two large-bore, 16- to 18-gauge IV crystalloid infusion to maintain volume
• Transfusions of whole blood and pRBCs as necessary
• Fresh frozen plasma and platelet transfusions for coagulopathy, with cryoprecipitate and fibrinogen given if indicated
• Follow hemoglobin/hematocrit and coagulation status.
• An attempt at vaginal delivery is reasonable; cesarean section recommended for maternal instability, nonreassuring fetal status, or when vaginal delivery is contraindicated (e.g., malpresentation, prior hysterotomy)
• Continuous fetal monitoring (Consider internal monitoring if in active labor.)
• Amniotomy or oxytocin administration can expedite delivery if not in active labor.
• Maternal positioning on left side enhances venous return and cardiac output.
• Oxygen as needed
• Saline or Ringer lactate to restore maternal vascular volume
• Frequent vital sign monitoring
• Record fluid ins and outs.
• Collect all pads/towels used to absorb blood for accurate estimates of blood loss.

Follow-up Recommendations

• Fetal growth surveillance with interval obstetric ultrasound
• Correction of maternal anemia
• Patient self-surveillance for symptoms of recurrent abruption
• Elective delivery at 37 to 39 weeks depending on the severity and preceding and stabilized abruption

Patient Monitoring
Severe cases or unstable patients may require critical care unit admission with readiness for surgical interventions, especially if undelivered.

Diet

Manage as potentially an acute obstetric surgical complication and thus NPO until reasonable stability is assured and possibility of immediate cesarean delivery is concluded.

Patient Education

• Call physician or proceed to hospital whenever patient experiences vaginal bleeding or if severe uterine or back pain or decreased fetal movement occurs.
• Wear seat belts while in an automobile.
• Discontinue use of cocaine and tobacco.
• Visit Mayo Clinic: http://www.mayoclinic.org/diseases-conditions/placental-abruption/basics/d....

Prognosis

• 0.5–1% in utero fetal mortality, depending on size of abruption; after delivery, up to 30–50% neonatal mortality, especially if compounding prematurity
• Abruption in context of major trauma carries 1% maternal and 30–70% fetal mortality.

Complications

• Acutely, maternal risks result from end-organ hypoxemic insults.
• Whole blood transfusion may be needed to minimize hypovolemia, DIC, and severe anemia.
• In severe abruptions, blood may extravasate into the myometrium (Couvelaire uterus), and this is appreciated at cesarean. The Couvelaire uterus is atonic and prone to postpartum hemorrhage.
• Aggressive management of secondary uterine atony is needed to prevent DIC; however, atony is typically recalcitrant to standard therapies for postpartum hemorrhage; thus, such parturients are at high risk for requiring hysterectomy.

ICD-10

• O45.001 Prem separtn of placenta w coag defect, unsp, first tri
• O45.002 Prem separtn of placenta w coag defect, unsp, second tri
• O45.003 Prem separtn of placenta w coag defect, unsp, third tri
• O45.009 Prem separtn of placenta w coag defect, unsp, unsp trimester
• O45.011 Prem separtn of placenta w afibrinogenemia, first trimester
• O45.012 Prem separtn of placenta w afibrinogenemia, second trimester
• O45.013 Prem separtn of placenta w afibrinogenemia, third trimester
• O45.019 Prem separtn of placenta w afibrinogenemia, unsp trimester
• O45.021 Prem separtn of placenta w dissem intravasc coag, first tri
• O45.022 Prem separtn of placenta w dissem intravasc coag, second tri
• O45.023 Prem separtn of placenta w dissem intravasc coag, third tri
• O45.029 Prem separtn of placenta w dissem intravasc coag, unsp tri
• O45.091 Prem separtn of placenta w oth coag defect, first trimester
• O45.092 Prem separtn of placenta w oth coag defect, second trimester
• O45.093 Prem separtn of placenta w oth coag defect, third trimester
• O45.099 Prem separtn of placenta w oth coag defect, unsp trimester
• O45.8X1 Other premature separation of placenta, first trimester
• O45.8X2 Other premature separation of placenta, second trimester
• O45.8X3 Other premature separation of placenta, third trimester
• O45.8X9 Other premature separation of placenta, unsp trimester
• O45.90 Premature separation of placenta, unsp, unsp trimester
• O45.91 Premature separation of placenta, unsp, first trimester
• O45.92 Premature separation of placenta, unsp, second trimester
• O45.93 Premature separation of placenta, unsp, third trimester
• P02.1 Newborn affected by oth placental separation and hemorrhage

ICD-9

• 641.20 Premature separation of placenta, unspecified as to episode of care or not applicable
• 641.21 Premature separation of placenta, delivered, with or without mention of antepartum condition
• 641.23 Premature separation of placenta, antepartum condition or complication
• 649.30 Coagulation defects complicating pregnancy, childbirth, or the puerperium, unspecified as to episode of care or not applicable
• 649.31 Coagulation defects complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition
• 649.32 Coagulation defects complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication
• 649.33 Coagulation defects complicating pregnancy, childbirth, or the puerperium, antepartum condition or complication
• 649.34 Coagulation defects complicating pregnancy, childbirth, or the puerperium, postpartum condition or complication
• 762.1 Other forms of placental separation and hemorrhage affecting fetus or newborn

SNOMED

• 198910006 Placental abruption - delivered
• 198911005 Placental abruption - not delivered
• 198912003 Premature separation of placenta with coagulation defect
• 268803008 Fetus or neonate affected by abruptio placentae
• 415105001 placental abruption (disorder)