PAS Hemorrhage Risk

PAS Spectrum Risk

Placenta Accreta / Increta / Percreta Assessment

High-Yield Ultrasound Markers

Prior Cesarean Section (Weighted Rank 1)
Placenta Previa (Co-existing)
Multiple Placental Lacunae
Loss of retroplacental clear zone
Abnormal uterine-bladder interface
Exophytic mass (Extra-uterine extension)

Massive Transfusion (MTP)

WHO/FIGO Aligned Protocol: 1:1:1 Ratio (RBC : FFP : Platelets).

Hb Target> 7g/dL

Plt Target> 50k

Fib Target> 200mg/dL

Critical Bleeding RateExceeding 150mL / Minute

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

Primary Clinical Uses

Classifying the profound morbidity risk in patients presenting with placenta previa and prior cesarean sections.

Directing surgical planning (e.g., scheduled cesarean hysterectomy, massive transfusion protocols).

Pre-operative counseling regarding the extreme risk of catastrophic pelvic hemorrhage.

What is PAS?

Placenta Accreta Spectrum (PAS) involves abnormal trophoblast invasion into the myometrium. It is categorized into Accreta (attaches directly to myometrium), Increta (invades into myometrium), and Percreta (penetrates through serosa/bladder).

How it Works

Risk Amplification (Silver et al.)

Calculated Risk with Placenta Previa:	Exponential Increase
0 Prior Cesareans	3% risk of Accreta
1 Prior Cesarean	11% risk
2 Prior Cesareans	40% risk
3 Prior Cesareans	61% risk
4+ Prior Cesareans	67% risk

Key Ultrasound Markers

Multiple irregular placental lacunae ("Swiss cheese" appearance)

Loss of the normal retroplacental clear space

Myometrial thickness < 1 mm

Bridging vessels spanning from placenta into bladder wall (Percreta)

Last Comprehensive Review: 2026-07-17

In Recent Clinical News

Scanning Medical Journals

No new significant updates or guidelines matching this topic were found today. We will check again soon.

PAS Hemorrhage Risk

PAS Spectrum Risk

Massive Transfusion (MTP)

When to Use

Primary Clinical Uses

What is PAS?

How it Works

Risk Amplification (Silver et al.)

Key Ultrasound Markers

Clinical Pearls

Absolute Contraindications

Next Steps

Surgical Pathway (Confirmed Increta/Percreta)

The Evidence

Landmark References

Maternal morbidity associated with multiple repeat cesarean deliveries.

Placenta Accreta Spectrum.

Origins & History

A Man-Made Epidemic

In Recent Clinical News

PAS Hemorrhage Risk

PAS Spectrum Risk

Massive Transfusion (MTP)

When to Use

Primary Clinical Uses

What is PAS?

How it Works

Risk Amplification (Silver et al.)

Key Ultrasound Markers

Clinical Pearls

Absolute Contraindications

Next Steps

Surgical Pathway (Confirmed Increta/Percreta)

The Evidence

Landmark References

Maternal morbidity associated with multiple repeat cesarean deliveries.

Placenta Accreta Spectrum.

Origins & History

A Man-Made Epidemic

In Recent Clinical News