Management of Placenta Accreta Spectrum (PAS)
Cesarean hysterectomy with the placenta left in situ is the standard treatment for placenta accreta spectrum, with delivery recommended at 34-36 weeks of gestation at a level III or IV maternal care center with a multidisciplinary team experienced in managing this condition. 1
Diagnosis and Risk Assessment
Clinical risk factors remain equally important as ultrasound findings for diagnosis of PAS:
Ultrasound findings suggestive of PAS:
- Placental lacunae with turbulent flow
- Loss of clear space between placenta and myometrium
- Decreased retroplacental myometrial thickness (<1mm)
- Abnormalities of uterine serosa-bladder interface
- Extension of placenta into myometrium, serosa, or bladder 1
Preoperative Planning
Women with suspected PAS should be delivered at a level III or IV maternal care center 1
Assemble a multidisciplinary team including:
Preoperative preparation:
- Optimize hemoglobin levels
- Alert blood bank and establish massive transfusion protocol
- Consider ureteric stent placement if bladder involvement is suspected
- Administer antenatal corticosteroids if delivery planned before 37 weeks 2
Timing of Delivery
- Schedule delivery at 34-36 weeks of gestation to avoid emergency delivery for hemorrhage (occurs in ~50% of cases after 36 weeks) 1, 2
- Earlier delivery may be required in cases of:
- Persistent bleeding
- Preeclampsia
- Labor
- Rupture of membranes
- Fetal compromise
- Developing maternal comorbidities 1
Surgical Approach
Cesarean hysterectomy with placenta left in situ is the standard approach:
- Place patient in dorsal lithotomy position for optimal surgical visualization and access
- Consider vertical skin incision or wide transverse incisions (Maylard or Cherney)
- Inspect uterus after peritoneal entry to determine placental location and invasion depth
- Make uterine incision away from placenta when possible
- Do not disturb or attempt to remove the placenta during delivery
- Rapidly close uterine incision and proceed with hysterectomy 1
Total hysterectomy is typically required as lower uterine segment or cervical bleeding frequently precludes supracervical hysterectomy 1
Blood Product Management
- Follow a 1:1:1 to 1:2:4 ratio of packed red cells:fresh frozen plasma:platelets 1, 2
- Monitor fibrinogen levels and maintain >200 mg/dL
- Consider 1g IV tranexamic acid within 3 hours of delivery, repeated after 30 minutes if bleeding persists
- Implement cell salvage if available 2
Conservative Management Considerations
- Conservative management (removing placenta without hysterectomy) or expectant management (leaving placenta in situ) should be considered only for carefully selected cases after detailed counseling about risks 1
- Conservative approaches are contraindicated in cases of sepsis or hemodynamic instability 2
- Failure rates of expectant management:
- 44% in patients with placenta percreta
- 7% in those with less extensive defects 1
- Severe adverse complication rates with expectant management:
- 17% in patients with placenta percreta
- 5% in those without percreta 1
Management of Complications
For sepsis:
- Broad-spectrum antibiotics (carbapenem or extended-range penicillin/β-lactamase inhibitor plus aminoglycoside)
- Add vancomycin or linezolid if MRSA risk or hemodynamic instability
- Monitor with serial lactate measurements and daily blood cultures until clearance 2
For hemorrhage:
Post-Operative Care
- Intensive hemodynamic monitoring in ICU setting
- Vigilance for ongoing bleeding
- Monitor for complications:
- Renal failure
- Liver dysfunction
- Disseminated intravascular coagulation
- Pulmonary edema
- Infection 2
By following this structured approach with appropriate multidisciplinary expertise, maternal morbidity and mortality associated with placenta accreta spectrum can be minimized.