🩸 Placental Abruption

Course Overview

Placental abruption is a critical obstetric condition characterized by the premature separation of a normally implanted placenta from the uterine wall before the delivery of the fetus. It is a significant cause of maternal morbidity, perinatal morbidity, and mortality. Early recognition, timely intervention, and appropriate supportive care are essential for optimal maternal and fetal outcomes.

This module provides an in-depth understanding of the risk factors, clinical features, diagnostic work-up, and evidence-based management strategies for placental abruption.

Learning Objectives

By the end of this module, learners should be able to:

1. Define placental abruption and explain its pathophysiology.

2. Identify predisposing and risk factors for placental abruption.

3. Recognize the clinical presentation and differentiate from other causes of antepartum haemorrhage.

4. Perform essential investigations to assess maternal and fetal status.

5. Formulate management plans based on gestational age, fetal viability, and maternal haemodynamic stability.

6. Implement supportive care measures and strategies to prevent maternal and fetal complications.

 Description

Placental abruption is defined as the premature separation of a normally located placenta from the uterine wall prior to delivery of the fetus. The extent of separation may vary, leading to either partial or complete detachment. Bleeding may be apparent per vaginam (overt) or concealed behind the placenta. The separation can compromise maternal hemodynamics and result in fetal hypoxia or demise.

 Risk Factors

The risk of placental abruption is increased in the presence of several maternal and obstetric conditions:

• Abdominal trauma (e.g., motor vehicle accidents, falls, or direct blows).

• Hypertensive disorders of pregnancy (chronic hypertension or preeclampsia).

• Premature rupture of membranes (PROM), particularly with sudden decompression of the uterus.

• Maternal anaemia.

• Thrombophilias (coagulation disorders).

• Iatrogenic procedures such as external cephalic version (ECV).

Other contributory factors may include maternal smoking, multiparity, advanced maternal age, and previous history of abruption.

 Clinical Presentation

Placental abruption typically presents with:

• Per vaginal bleeding: usually dark red and may contain clots. In some cases, bleeding may be concealed.

• Lower abdominal pain: often sudden, severe, and continuous.

• Changes in fetal movements: either increased or decreased perception.

• Signs of maternal anaemia or shock: pallor, tachycardia, hypotension.

On abdominal examination:

• The uterus is tense, tender, and woody hard on palpation.

• Presentation and lie may remain normal, especially at term.

• Fetal heart rate may be absent if fetal demise has occurred or may show signs of fetal distress if the fetus is still viable.

The clinical picture may progress rapidly, requiring immediate intervention to prevent maternal or fetal compromise.

 Diagnostic Investigations

Evaluation of placental abruption is primarily clinical, but laboratory and supportive investigations are essential:

• Full blood count (FBC) to assess haemoglobin and haematocrit.

• Blood grouping and cross-match for red cell concentrates (RCCs), fresh frozen plasma (FFP), and platelets.

• Bedside clotting time and full coagulation profile to assess coagulopathy.

• Renal function tests (RFTs) to monitor for hypoperfusion or hemolysis.

• Obstetric ultrasound is not always required, but may help assess fetal viability, placental location, and retroplacental hematoma.

 Management Principles

Management depends on maternal haemodynamic status, gestational age, and fetal viability.

A. Viable Fetus at or Near Term

• Emergency caesarean section is indicated regardless of maternal stability to optimize fetal outcome.

• Preparation includes establishing two large-bore intravenous lines (14–18 gauge), ensuring availability of cross-matched blood products, and setting up continuous fetal and maternal monitoring.

B. Demised Fetus with Maternal Stability

If the fetus is already demised and the mother is haemodynamically stable, expectant or supportive management may be pursued:

1. Admission to high-dependency or monitored ward.

2. Two large-bore IV lines to maintain rapid fluid and blood product access.

3. Blood products: RCCs, FFP, platelets, and cryoprecipitate should be cross-matched, with an aim to transfuse up to six units before delivery if needed.

4. Urinary catheterization for strict input-output monitoring.

5. Digital vaginal examination to assess the Bishop score prior to induction of labour.

6. Labour induction or augmentation: if in established labour, expedite delivery with amniotomy and oxytocin infusion (2.5–5 IU in 500 mL normal saline or Ringer’s lactate).

7. Rapid intravenous fluid replacement: 1 L Ringer’s lactate over 30 minutes.

8. Tranexamic acid 1 g IV stat, ideally administered within 3 hours of onset of bleeding.

9. Analgesia: pethidine 100 mg, fentanyl 100 mcg, or morphine 15 mg IM.

10. Continuous maternal monitoring: vital signs, oxygen saturation, and urine output.

11. Presence of a medical officer at the 2nd and 3rd stages of labour to anticipate postpartum haemorrhage due to both uterine atony and coagulopathy.

12. Active management of the third stage of labour (AMTSL).

13. Estimate total blood loss, including concealed retroplacental clots.

C. Maternal Instability or Active Bleeding

If the patient is haemodynamically unstable or bleeding actively, prepare for immediate caesarean section, irrespective of fetal condition. Rapid resuscitation, fluid replacement, blood transfusion, and multidisciplinary team involvement are crucial.

 Complications and Considerations

Placental abruption may result in:

• Maternal complications: hemorrhagic shock, disseminated intravascular coagulation (DIC), renal failure, and multi-organ failure.

• Fetal complications: hypoxia, growth restriction, preterm birth, or intrauterine fetal demise.

• Delivery complications: increased risk of postpartum haemorrhage, need for hysterectomy in severe cases, and coagulopathy.

Multidisciplinary management, including obstetricians, anesthetists, hematologists, and neonatologists, is essential for optimizing outcomes.

 Key Summary Points

• Placental abruption is the premature separation of a normally implanted placenta.

• It presents with dark red vaginal bleeding, abdominal pain, and uterine tenderness, often with fetal distress.

• Maternal haemodynamic status and fetal viability guide management.

• Emergency caesarean section is indicated for a viable fetus at or near term or if maternal instability occurs.

• Supportive care for stable patients includes blood transfusion, IV fluids, analgesia, monitoring, and labour augmentation if indicated.

• Early recognition and prompt intervention are critical to prevent maternal and fetal morbidity and mortality.

Recommended References

• Cunningham FG et al. Williams Obstetrics, 27th Edition.

• American College of Obstetricians and Gynecologists (ACOG). Practice Bulletin No. 183: Postpartum Hemorrhage, 2017.

• NICE Guidelines NG201 (2021): Intrapartum Care: Care of Healthy Women and Their Babies During Childbirth.

• Ministry of Health Zambia. Obstetric Care Protocols.