Chronic Placental Abruption: Causes and Risk Factors

Chronic Placental Abruption

It is under-recognized, often ultrasound-subtle, and clinically important because it primarily causes uteroplacental insufficiency rather than hemorrhagic shock.

Definition
• Recurrent or ongoing small placental separations over time
• Usually retroplacental or marginal
• Bleeding is often concealed rather than external

Pathophysiology
• Repeated micro-hemorrhages at the decidual–placental interface
• Formation of organized hematoma, fibrin deposition, placental infarction
• Progressive reduction in functional placental surface area
• Leads to chronic hypoxia, not acute fetal compromise

Risk factors
• Previous placental abruption
• Chronic hypertension
• Preeclampsia
• Smoking, cocaine
• Thrombophilias (especially acquired)
• Trauma
• Uterine anomalies
• Advanced maternal age
• IUGR in prior pregnancy

Clinical presentation

Maternal
• Recurrent spotting or brownish discharge
• Intermittent abdominal pain or uterine irritability
• Often hemodynamically stable
• May have anemia over time

Fetal
• Fetal growth restriction (most common clue)
• Reduced fetal movements
• Oligohydramnios
• Non-reassuring fetal testing in advanced cases

MUltrasound findings (often subtle)

Placental features
• Retroplacental hypoechoic or heterogeneous area
• Thickened placenta
• Irregular placental–myometrial interface
• Placental lakes with echogenic margins (old bleed)
• Subchorionic or marginal hematoma

Amniotic fluid
• Oligohydramnios common

Doppler findings
• Elevated umbilical artery PI
• Abnormal uterine artery Doppler
• MCA brain-sparing in advanced disease
• Abnormal CPR

Differentiation from acute abruptiondisease

  Feature   Chronic abruption   Acute abruption
  Onset   Gradual   Sudden
  Bleeding   Minimal or concealed   Heavy, painful
  Maternal shock   Rare   Common
  Fetal effect   Chronic hypoxia, FGR   Acute distress or demise
  Ultrasound   Subtle   Often normal

Maternal and fetal risks

Fetal
• Fetal growth restriction
• Preterm birth
• Oligohydramnios
• Stillbirth (usually late and related to chronic hypoxia)

Maternal
• Recurrent bleeding
• Acute abruption superimposed on chronic
• Rarely DIC

Management (gestation-dependent)

Previable / early viable (<28 weeks)
• Expectant management if stable
• Close surveillance:
o Serial growth scans
o Dopplers
o AFI
• Corticosteroids if preterm risk

28–34 weeks
• Intensified fetal surveillance
• Admit if recurrent bleeding or Doppler deterioration
• Steroids ± magnesium sulfate
• Delivery if fetal compromise

≥34–36 weeks
• Low threshold for delivery
• Earlier if:
o Worsening Dopplers
o Reduced movements
o Recurrent bleeding

Counseling
• This is a placental function problem, not an infection or genetic issue
• The goal is timing delivery, not curing the placental disease
• Risk of sudden deterioration exists but is REMOTE
• Close follow-up improves outcomes significantly