BASICS
DESCRIPTION
Premature separation of an otherwise normally implanted placenta due to bleeding at the decidual-placental interface
EPIDEMIOLOGY
Incidence
- 0.3-1% of pregnancies are complicated by placental abruption (1).
- 0.94-1.4% of all deliveries (2):
- Placental abruption is the most common cause of serious vaginal bleeding in late pregnancy.
- 80% of cases occur prior to onset of delivery.
- 40-60% occur before 37 weeks of gestation; 14% occur before 32 weeks.
- Rates of placental abruption have been rising in the United States (2).
ETIOLOGY AND PATHOPHYSIOLOGY
- Acute
- Trauma of variable amounts, especially blunt abdominal trauma in which external signs of trauma may be incongruent with fetal injury.
- Sudden decompression of overdistended uterus, as in rupture of membranes with polyhydramnios or twin gestation
- Vasospasm secondary to cocaine use
- Uterine abnormalities: bicornuate uterus, uterine synechiae, leiomyomas, prior hysterotomy
- Chronic (majority of cases)
- Hypertensive disorders and growth restriction associated with chronic process
- Early bleeding in pregnancy releases thrombin, which is a potent uterotonic agent.
- Smoking
- Exact cause is unknown: appears to be the final common clinical event secondary to a variety of causes (3)
Genetics
- No firm evidence, but some authors suggest genetic predisposition may be the cause of abruption in women with no other inciting factor discovered.
- Placental growth is primarily under control of paternally inherited fetal genes.
RISK FACTORS
- Prior abruption: increases 15- to 20-fold
- Increasing maternal age and parity
- Maternal smoking: 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 (3)
GENERAL PREVENTION
Eliminate risk factors when possible: Quit smoking and cocaine use, control hypertension, use seat belts, and so forth.
COMMONLY ASSOCIATED CONDITIONS
- Preeclampsia and other forms of hypertension in pregnancy
- Uteroplacental insufficiency
- Postpartum hemorrhage
- Disseminated intravascular coagulation (DIC)
- Rupture of membranes
DIAGNOSIS
HISTORY
- Classic triad of vaginal bleeding, abdominal pain, and contractions
- Abruption in prior pregnancy
- Early trimester bleeding
- Recent trauma
- Cocaine or tobacco use
- Back pain
- Frequent or tetanic contraction
- May present in active labor
- Recent rupture of membranes
PHYSICAL EXAM
- Vital signs: tachycardia, hypotension. Because blood volumes increase in pregnancy, volume loss may exceed 30% before signs of shock or hypovolemia occur.
- Uterine tenderness, hypertonia, or high-frequency contractions
- Vaginal bleeding (not always present): Clinical signs of shock may occur with little vaginal bleeding.
- Fetal distress or demise
- Idiopathic preterm labor with or without fetal distress
DIFFERENTIAL DIAGNOSIS
- Placenta previa or vasa previa (4)
- 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 (5).
- Prothrombin time (PT)/partial thromboplastin time (PTT)
- Kleihauer-Betke test checks for evidence of fetal blood in maternal circulation; >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.
- Bedside clot test: red-top tube of maternal blood with poor or nonclotting blood after 7 to 10 minutes indicates coagulopathy.
- 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 (6).
- With acute bleed, nothing may be seen.
- 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
- 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.
TREATMENT
MEDICATION
First Line
- Tocolytics are generally contraindicated in presence of abruption (7)[B]
- Tocolytics such as nifedipine and indomethacin may be used in nonsevere abruption before 34 weeks (generally to administer 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
Second Line
- Transfuse packed red blood cells (PRBC) or other factors to stabilize patient as needed
- Steroids for fetal lung maturation, if fetus is viable and <34 weeks' gestational age (8)[A]
- Magnesium for CP prophylaxis should be considered in any patient <32 weeks' gestational age (9)[A].
ISSUES FOR REFERRAL
- If preterm and hemodynamically stable, refer to tertiary care center.
- Alert anesthesiologists so they can evaluate the patient prior to any emergent procedures.
SURGERY/OTHER PROCEDURES
- May need cesarean delivery after maternal stabilization if fetus is viable, remote from delivery, and nonreassuring fetal heart tracing is present.
- Postpartum hemorrhage/DIC may be treated medically or with uterine packing, embolization, or hysterectomy.
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
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 weeks but the risk of developing a severe abruption is high (10)[B].
- 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 restraints
- Early aggressive restoration of maternal physiology to protect fetus and maternal organs from hypoperfusion/DIC
- Stabilize vitals.
- Bed rest 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.
- Attempted vaginal delivery is reasonable. Cesarean section recommended for maternal instability, nonreassuring fetal status, or when vaginal delivery contraindicated (e.g., malpresentation, prior hysterotomy)
- Attempt to restore coagulopathies prior to cesarean section.
- Continuous fetal monitoring (consider internal monitoring in active labor)
- Amniotomy or oxytocin administration can expedite delivery if not in active labor.
- Positioning on left side may enhance venous return and cardiac output.
- Oxygen as needed
IV Fluids
Saline or Ringer lactate to restore maternal vascular volume
Nursing
- Frequent vital sign monitoring
- Record fluid ins and outs.
- Collect all pads/towels used to absorb blood for accurate estimates of blood loss.
Discharge Criteria
- 2nd trimester suspected abruption may be managed on outpatient basis if hemodynamically stable.
- Viable patients may be discharged if maternal/fetal status is stable.
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
- Monthly growth ultrasonograms for those patients where conservative management is possible (11)[C]
- Serial ultrasounds may also be used to follow regression or progression of abruption.
- Pelvic rest
Patient Monitoring
Severe cases or unstable patients may require critical care unit admission.
DIET
NPO until status is defined and possibility of immediate cesarean delivery ruled out.
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/definition/con-20024292.
PROGNOSIS
- 0.5-1% fetal mortality and 30-50% perinatal mortality: 1/2 of perinatal deaths due to preterm delivery
- With trauma and abruption, 1% maternal, and 30-70% fetal mortality
COMPLICATIONS
- Maternal complications include anemia, stroke, myocardial infarction, DIC, and Sheehan syndrome and may include maternal death with severe hemorrhage.
- Surgical interventions and transfusion carry their own morbidity/mortality.
- Amniotic fluid embolism is rare but may present with severe respiratory distress.
REFERENCES
11 Ananth CV, Keyes KM, Hamilton A, et al. An international contrast of rates of placental abruption: an age-period-cohort analysis.PLoS One. 2015;10(5):e0125246.22 Ananth CV, Oyelese Y, Yeo L, et al. Placental abruption in the United States, 1979 through 2001: temporal trends and potential determinants. Am J Obstet Gynecol. 2005;192(1):191-198.33 Ananth CV, Getahun D, Peltier MR, et al. Placental abruption in term and preterm gestations: evidence for heterogeneity in clinical pathways. Obstet Gynecol. 2006;107(4):785-792.44 Sakornbut E, Leeman L, Fontaine P. Late pregnancy bleeding. Am Fam Physician. 2007;75(8):1199-1206.55 de Lloyd L, Bovington R, Kaye A, et al. Standard haemostatic tests following major obstetric haemorrhage. Int J Obstet Anesth. 2011;20(2):135-141.66 Salihu HM, Bekan B, Aliyu MH, et al. Perinatal mortality associated with abruptio placenta in singletons and multiples. Am J Obstet Gynecol. 2005;193(1):198-203.77 Towers CV, Pircon RA, Heppard M. Is tocolysis safe in the management of third-trimester bleeding? Am J Obstet Gynecol. 1999;180(6 Pt 1):1572-1578.88 Roberts D, Dalziel SR. Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth. Cochrane Database Syst Rev. 2006;(3);CD004454.99 Doyle LW, Crowther CA, Middleton P, et al. Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus. Cochrane Database Syst Rev. 2009;(1):CD004661.1010 Oyelese Y, Ananth CV. Placental abruption. Obstet Gynecol. 2006;108(4):1005-1016.1111 Miller DA, Rabello YA, Paul RH. The modified biophysical profile: antepartum testing in the 1990s. Am J Obstet Gynecol. 1996;174(3):812-817.
ADDITIONAL READING
- Getahun D, Ananth CV, Peltier MR, et al. Acute and chronic respiratory diseases in pregnancy: associations with placental abruption. Am J Obstet Gynecol. 2006;195(4):1180-1184.
- Ozcan T, Pressman EK. Imaging of the placenta. Ultrasound Clinics. 2008;3(1):13-22.
- Tikkanen M. Placental abruption: epidemiology, risk factors and consequences. Acta Obstet Gynecol Scand. 2011;90(2):140-149.
- Yang Q, Wen SW, Oppenheimer L, et al. Association of caesarean delivery for first birth with placenta praevia and placental abruption in second pregnancy. BJOG. 2007;114(5):609-613.
CODES
ICD10
- O45.90 Premature separation of placenta, unsp, unsp trimester
- O45.8X9 Other premature separation of placenta, unsp trimester
- O45.029 Prem separtn of placenta w dissem intravasc coag, unsp tri
- O45.93 Premature separation of placenta, unsp, third trimester
- O45.8X1 Other premature separation of placenta, first trimester
- O45.022 Prem separtn of placenta w dissem intravasc coag, second tri
- O45.013 Prem separtn of placenta w afibrinogenemia, third trimester
- O45.021 Prem separtn of placenta w dissem intravasc coag, first tri
- O45.019 Prem separtn of placenta w afibrinogenemia, unsp trimester
- O45.091 Prem separtn of placenta w oth coag defect, first trimester
- O45.099 Prem separtn of placenta w oth coag defect, unsp trimester
- O45.093 Prem separtn of placenta w oth coag defect, third trimester
- O45.092 Prem separtn of placenta w oth coag defect, second trimester
- O45.92 Premature separation of placenta, unsp, second trimester
- O45.023 Prem separtn of placenta w dissem intravasc coag, third tri
- O45.8X2 Other premature separation of placenta, second trimester
- O45.8X3 Other premature separation of placenta, third trimester
- O45.91 Premature separation of placenta, unsp, first trimester
- 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
- O45.001 Prem separtn of placenta w coag defect, unsp, first tri
- O45.011 Prem separtn of placenta w afibrinogenemia, first trimester
- O45.012 Prem separtn of placenta w afibrinogenemia, second trimester
- P02.1 Newborn affected by oth placental separation and hemorrhage
ICD9
- 641.20 Premature separation of placenta, unspecified as to episode of care or not applicable
- 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
- 641.21 Premature separation of placenta, delivered, with or without mention of antepartum condition
- 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
- placental abruption (disorder)
- Placental abruption - not delivered
- Premature separation of placenta with coagulation defect
- Placental abruption - delivered
- Fetus or neonate affected by abruptio placentae
CLINICAL PEARLS
- Placental abruption is the most common cause of serious vaginal bleeding in late pregnancy.
- Abruption is a clinical diagnosis. The classic triad is vaginal bleeding, abdominal pain, and contractions. Ultrasound can help to make the diagnosis, but it has low sensitivity and is only helpful in cases of a large abruption.
- Because blood volumes increase in pregnancy, volume lost may exceed 30% before signs of shock or hypovolemia occur.
- Individualize management on a case-by-case basis, depending on maternal and fetal considerations.