Disclaimer

There is currently no dedicated NICE guideline specifically addressing placental abruption. The RCOG Green-top Guideline No. 63: Antepartum Haemorrhage (published 2011) includes placental abruption, but its coverage is non-specific and has not been updated in over 10 years.

Therefore, this article is based primarily on BMJ Best Practice clinical guidance​​​​​.

Background Information

Definition

Separation of the placenta from the uterus prior to delivery.

Causes and Risk Factors

Lifestyle Factors

• Smoking
• Cocaine use (and other stimulants)
• Alcohol misuse
• Low BMI

Maternal Conditions

• Hypertension – most common cause
• Pre-eclampsia
• Autoimmune disease (e.g. antiphospholipid syndrome)
• Thrombophilia

Pregnancy Factors

• Maternal age
  • < 20 y/o
  • >35 y/o

• Previous placental abruption – strongest risk factor
• Multiple pregnancy
• Trauma to the abdomen
• Polyhydramnios
• Assisted reproductive technologies (e.g. IVF)

Clinical Features

Onset: >20 weeks (esp. third trimester)

Sudden onset of:

• Abdominal pain 
• ‘Woody‘ tender uterus
• Vaginal bleeding (may be ‘concealed’ / not be present) – major cause of antepartum haemorrhage

Other:

• Foetal heart rate abnormalities (such as nonreassuring fetal status or fetal distress)
• Severe cases → Maternal shock (tachycardia, hypotension etc.) / DIC 

Gudielines

Investigation and Diagnosis

Placental abruption is mainly a clinical diagnosis

Blood Tests

• FBC (including haemoglobin and haematocrit)
• Clotting studies

Imaging

1st line: ultrasound

• May show retroplacental haematoma
  • Detection rate is low; ~12-25%
  • Negative ultrasound does not exclude abruption
• Useful for excluding placenta praevia (DDx antepartum haemorrhage)

Fetal Monitoring

Perform continuous cardiotography

• Fetal well-being is important in guiding management

Management

Stabilise the mother and resuscitate as needed.

Definitive management depends on 1) fetal status and 2) weeks of gestation, with exceptions:

• Unstable maternal status → urgent Caesarean section (regardless of fetal status and weeks of gestation)
• Intrauterine fetal demise (dead fetus)→ vaginal delivery (usually with induction)

Non-reassuring fetal status is evidenced by several suspicious / abnormal CTG features (further detail on NICE ‘fetal monitoring in labour’): ^[Ref]

• Fetal bradycardia (baseline heart rate <110 bpm)
• Prolonged decelerations (>3 minutes)
• Late decelerations
• Loss of baseline variability
• Persistent tachycardia

The most critical findings are acute sustained bradycardia or prolonged deceleration, which reflect acute fetal hypoxia and warrant urgent obstetric review for expedited delivery

References

Original Guideline