Placental abruption: Clinical sciences

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Introduction0:00–0:44

Placental abruption is the partial or complete separation of the placenta from the uterine wall prior to delivery. This is due to rupture of maternal vessels within the basal layer of the endometrium.
Blood accumulates and splits the placental attachment, which can cause leakage of blood into the myometrium, painful uterine contractions, as well as maternal blood loss through the vagina, which results in decreased blood flow and oxygenation to the fetus.
Some patients may present acutely requiring immediate delivery, while others may stabilize and be candidates for expectant management of the pregnancy with close surveillance.When evaluating a patient presenting with a chief concern suggesting placental abruption, your first step is to perform a CABCDE assessment as well as a primary obstetric survey to determine if they are stable or unstable.

Unstable0:44–4:28

If the patient is unstable, immediately attempt to control the hemorrhage and stabilize their airway, breathing, and circulation.
You may need to intubate the patient, obtain IV access, and continuously monitor their vitals. Remember that you have two patients here, so you must assess the fetus as well!
First, check the fetal heart rate to ensure well-being, and if at a viable gestational age, perform continuous fetal monitoring and assess for fetal movement.
Bleeding from a placental abruption can stimulate uterine contractions, so you should also assess for labor. Once you have initiated the acute management, your next step is a focused history and physical exam.
Labs are important because of the potential for life-threatening hemorrhage, so order a CBC as well as PT, INR, PTT, and fibrinogen.
Finally, order a Kleihauer-Betke test, also called a “KB” for short, to look for the presence of fetal blood in maternal circulation.
This test is highly specific for abruption and lets you know how much Rh immune globulin is needed to prevent alloimmunization.In the history, patients may report feeling dizzy or anxious, and may experience tunnel vision due to the acute hemorrhage.
In addition, they’ll typically report abdominal pain and contractions. Next, be sure to review the patient’s risk factors for abruption.
These include tobacco or cocaine use; abdominal trauma; preterm prelabor rupture of membranes; advanced maternal age; uterine myomas; a history of abruption in a prior pregnancy; or a hypertensive disorder, such as gestational hypertension, preeclampsia, or chronic hypertension.Here’s a clinical pearl!
Painful vaginal bleeding after 20 weeks often indicates a placental abruption. With painless vaginal bleeding, think placenta previa.As for the physical exam, expect hypotension, tachycardia, and an altered mental status.
Patients may look pale and their skin could feel cold or clammy. Typically, patients will have vaginal bleeding coming from the uterus, but in cases known as a concealed abruption, the blood can pool behind the placenta, so there won’t be vaginal bleeding.
Blood leaking into the myometrium may make the uterus tender, firm, and hypertonic on the exam. Now, the rupture of vessels that provide maternal blood to the fetus and the loss of functional placental surface can cause fetal distress.
The fetal heart rate tracing may show recurrent late decelerations or even fetal bradycardia. Additionally, the tocometer often shows high frequency, low amplitude contractions, and increased uterine resting tone.
Because some women with abruption present without vaginal bleeding, keep abruption in mind for women who present with decelerations and uterine irritability during monitoring.Now let’s talk about labs.
Anemia is common in abruption. In addition, there may also be low platelets, elevated PT, INR, and PTT, as well as low fibrinogen as coagulation factors are consumed.
Lastly, labs may also show a positive KB.Alright, based on these findings on history, physical, and labs, you can diagnose placental abruption with hemorrhage and shock.

Management4:28–5:52

Start IV fluid resuscitation quickly, and be prepared to give blood products, even if labs seem reassuring. Remember that labs may not reflect the degree of blood loss, since hemorrhage can rapidly evolve, and it takes time for lab values to reflect that.
Therefore, the patient’s clinical picture and vitals should serve as the main indicators for transfusion.With unstable patients, you will need to deliver the fetus.
Patients can labor quickly with abruption, so a vaginal delivery might be possible if they’re very close to delivery; otherwise, perform a C-section.
Patients with Rh-negative blood types need Rh immune globulin. The KB test can help tell you how much Rh immune globulin is needed based on the volume of fetal blood in maternal circulation.Here's a high-yield fact!
Sometimes during a C-section for placental abruption, you will see a port wine coloring to the uterus from blood penetrating the myometrium up to the serosa.
This is called a Couvelaire uterus, and because the blood in the myometrium inhibits uterine contraction, the patient is at high risk for uterine atony and postpartum hemorrhage.Managing unstable patients can be scary, but not all patients with placental abruption will present that urgently; let’s now talk about stable patients!

Stable5:52–7:44

Your first step is to obtain a focused history and physical, then get labs including CBC, PT, INR, PTT, fibrinogen, and KB.
Also, be sure to obtain an obstetric ultrasound.When it comes to history, abruption can happen at any time after 20 weeks of gestational age, but most occur in the third trimester, and patients typically report abdominal pain and contractions.
Risk factors are the same as those found in an unstable patient. So, history might reveal tobacco or cocaine use; abdominal trauma; preterm prelabor rupture of membranes; advanced maternal age; uterine myomas; a history of abruption in a prior pregnancy; or a hypertensive disorder.
On a physical exam, most patients have vaginal bleeding from the uterus, which can be tender and feel firm and hypertonic.
Fetal heart tracing could show intermittent late decelerations, and the tocometer might have high frequency and low amplitude contractions with increased uterine resting tone.
Labs could reveal anemia, thrombocytopenia, elevated PT, INR, PTT, and low fibrinogen; and may also show a positive KB.Now, obstetric ultrasound may demonstrate blood behind the placenta.
However, ultrasound is not very sensitive for abruption, so don’t be surprised if it’s normal. Make sure there’s no evidence of a placenta previa, as this is an important differential diagnosis.With these findings on history, physical, labs, and ultrasound you can make the diagnosis of placental abruption.

Management 7:44–9:59

Remember, placental abruption is a clinical diagnosis based on history and physical exam, while labs and ultrasound are used to support that clinical diagnosis and exclude other things from the differential.Now that we have a diagnosis, there are a few more things to consider in planning management.
Start by assessing for a non-reassuring fetal status; evidence of a new or worsening anemia; an evolving coagulopathy; active vaginal bleeding; and ongoing contractions or evidence of labor.
If one or more of these criteria are present, the patient is not a candidate for expectant management, so you should move toward delivery.
Patients may labor quickly with an abruption, so you can try for a vaginal delivery if they have minimal vaginal bleeding and a reassuring fetal status.
However, if the fetal status is non-reassuring, bleeding is heavy, coagulopathy is developing, or there are other standard contraindications to labor, move towards C-section.
Additionally, don’t forget Rh immune globulin for Rh-negative patients. On the flip side, if your evaluation shows a reassuring fetal status without evidence of anemia, coagulopathy, ongoing vaginal bleeding, persistent contractions, or indications of labor, you can expectantly manage your patient.
First, if your patient is Rh-negative and hasn’t received Rh Immune globulin within the last 12 weeks, be sure to give the medication within 72 hours of their bleeding episode.
Close antenatal fetal surveillance with non-stress tests, biophysical profiles, growth ultrasounds, and measurements of amniotic fluid volume are also needed.
Additionally, if the patient presents before 37 weeks of gestation, antenatal steroids should be considered if there’s an imminent risk of delivery within the next week.
There’s not much data to guide the timing of delivery for patients experiencing a stable placental abruption, but delivery in the early term or late preterm period is usually recommended.
Alright, as a quick recap… Placental abruption is the separation of the placenta prior to delivery. This is a clinical diagnosis based on history and physical exam, with labs and imaging supporting the decision.

Review9:59–11:08

Unstable patients should undergo rapid fetal assessment and resuscitation while receiving aggressive fluid and blood product replacement, with a plan for immediate delivery.
Stable patients should be assessed for immediate delivery or expectant management. If there’s a non-reassuring fetal status, evidence of new or worsening anemia, an evolving coagulopathy, active vaginal bleeding, or persistent contractions or labor, then proceed with delivery.
If none of these criteria are present, you can expectantly manage until the late preterm or early term period, with close fetal surveillance and consideration of antenatal steroids.
Finally, assess all Rh-negative patients experiencing placental abruption for Rh immune globulin, which can be dosed based on a
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