How to diagnose placental abruption (placenta abruptio)?

From the Guidelines

Ruling out placental abruption requires a comprehensive clinical assessment combined with diagnostic testing, prioritizing ultrasound imaging as the mainstay of diagnosis, as recommended by the American College of Radiology in 2020 1. To rule out placental abruption, the following steps should be taken:

• Evaluate for classic symptoms including vaginal bleeding, abdominal pain, uterine tenderness or contractions, and fetal distress.
• Perform a complete physical examination focusing on vital signs, abdominal examination, and fetal heart rate monitoring.
• Order laboratory tests including a complete blood count to check for anemia, coagulation studies to assess for disseminated intravascular coagulation, and a Kleihauer-Betke test to detect fetal-maternal hemorrhage.
• Ultrasound imaging, particularly transabdominal and transvaginal US, is essential for making accurate diagnoses and guiding management, as it can help identify placental abruption, placenta previa, and other potential causes of vaginal bleeding 1. Some key points to consider:
• Placental abruption affects approximately 1% of pregnancies, but US diagnosis is much less common and likely identifies, at most, 50% of cases of abruption 1.
• Risk factors to consider include trauma, hypertension, cocaine use, smoking, advanced maternal age, and previous abruption.
• The diagnosis is often one of exclusion and clinical judgment, as no single test definitively rules out abruption.
• In uncertain cases with stable maternal and fetal status, close observation with continuous fetal monitoring for 24 hours may be necessary.
• Severe cases may require emergency delivery regardless of gestational age, and the management of placental abruption should be guided by the severity of the condition and the presence of fetal distress or other complications 1.

From the Research

Ruling Out Placental Abruption

To rule out placental abruption, the following steps can be taken:

• A thorough clinical evaluation is necessary, as the diagnosis of placental abruption is primarily clinical 2, 3, 4
• Risk factors for abruption should be identified, including prior abruption, smoking, trauma, cocaine use, multifetal gestation, hypertension, preeclampsia, thrombophilias, advanced maternal age, preterm premature rupture of the membranes, intrauterine infections, and hydramnios 2, 5, 6
• Ultrasonography may be used to evaluate the placenta, but its value is limited in diagnosing abruption 2, 4
• The Kleihauer-Betke test may also be used, but its value is limited in diagnosing abruption 2
• Fetal heart rate monitoring and maternal vital signs should be closely monitored to assess fetal and maternal well-being 4, 6

Key Considerations

• Placental abruption can present with varying degrees of severity, from asymptomatic to severe maternal and fetal morbidity 3, 6
• The management of abruption should be individualized based on the severity of the abruption, gestational age, and fetal and maternal status 2, 4, 5
• In cases of severe abruption, prompt delivery by cesarean may be necessary to optimize maternal and fetal outcomes 2, 6
• In cases of mild abruption, conservative management with close monitoring may be appropriate, but the risk of deterioration should be carefully assessed 2, 4, 5