MATERNAL CARDIAC ARREST AND OBSTETRIC RESUSCITATION

From Immediate Recognition to Resuscitative Hysterotomy

International Scientific Update 2026

AHA • ILCOR • ERC • ACOG • SMFM • RCOG • ATLS • PHTLS • ITLS

DrRamonReyesMD
EMS Solutions International

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INTRODUCTION

Maternal cardiac arrest is one of the most challenging emergencies in modern medicine.

Few clinical situations require healthcare professionals to simultaneously fight for two lives while managing profound physiological alterations, severe hypoxia, circulatory collapse, and an extremely narrow therapeutic window.

Although relatively uncommon, maternal cardiac arrest remains associated with significant maternal and fetal mortality when recognition or intervention is delayed.

Current estimates suggest an incidence ranging from approximately 1 in 12,000 to 1 in 30,000 pregnancies depending on population characteristics and healthcare systems. The true burden is likely underestimated in low-resource settings. DOI: 10.1016/S0140-6736(16)31470-2

The most important principle is straightforward:

A pregnant patient in cardiac arrest cannot be managed exactly like a non-pregnant adult.

Pregnancy profoundly alters cardiovascular, respiratory, hematologic, and metabolic physiology. These changes directly influence the effectiveness of cardiopulmonary resuscitation (CPR) and require specific modifications to standard Advanced Cardiac Life Support (ACLS) protocols.

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TERMINOLOGY

Historically, the term Perimortem Cesarean Section (PMCS) was widely used.

Modern literature increasingly favors:

Resuscitative Hysterotomy (RH)

This terminology better reflects the primary objective of the procedure:

Maternal resuscitation.

Fetal survival is important but secondary.

The procedure is fundamentally a resuscitative intervention designed to improve maternal circulation.

DOI: 10.1016/j.ajog.2015.07.019

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DEFINITION OF MATERNAL CARDIAC ARREST

Maternal cardiac arrest is defined as the abrupt cessation of effective cardiac mechanical activity occurring during pregnancy or the peripartum period.

Clinical findings include:

• Unresponsiveness
• Absence of a central pulse
• Absence of normal breathing
• Requirement for immediate CPR

Without prompt intervention, irreversible cerebral injury develops within minutes.

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WHY PREGNANCY CHANGES CPR

The most important physiological factor is:

Aortocaval Compression

Beginning at approximately 20 weeks' gestation, the gravid uterus compresses:

• Inferior vena cava
• Abdominal aorta

This results in:

• Reduced venous return
• Reduced preload
• Reduced cardiac output
• Reduced coronary perfusion
• Reduced cerebral perfusion
• Reduced uteroplacental blood flow

These effects significantly compromise the effectiveness of CPR.

DOI: 10.1161/CIR.0000000000000300

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MATERNAL PHYSIOLOGICAL CHANGES

Pregnancy is associated with:

Cardiovascular Changes

• 30–50% increase in cardiac output
• Increased plasma volume
• Increased heart rate
• Reduced systemic vascular resistance

Respiratory Changes

• Increased oxygen consumption
• Reduced functional residual capacity
• Elevated diaphragm
• Rapid oxygen desaturation during apnea

Airway Changes

• Airway edema
• Increased vascularity
• Increased risk of difficult intubation

Gastrointestinal Changes

• Delayed gastric emptying
• Increased aspiration risk

These physiological changes make airway management particularly challenging during maternal resuscitation.

DOI: 10.1097/AOG.0000000000004021

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COMMON CAUSES OF MATERNAL CARDIAC ARREST

The differential diagnosis extends beyond traditional ACLS causes.

Major etiologies include:

Obstetric Hemorrhage

• Placenta previa
• Placental abruption
• Uterine rupture
• Postpartum hemorrhage

Amniotic Fluid Embolism

A rare but catastrophic obstetric emergency.

Pulmonary Embolism

Pregnancy is a hypercoagulable state.

Severe Preeclampsia and Eclampsia

Peripartum Cardiomyopathy

Sepsis

Anesthetic Complications

Trauma

Motor vehicle collisions remain a leading cause of non-obstetric maternal death.

DOI: 10.1016/S0140-6736(16)31470-2

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BASIC LIFE SUPPORT IN PREGNANCY

The foundations remain unchanged:

• Recognize arrest
• Activate emergency response
• Begin high-quality CPR
• Defibrillate when indicated

However, one modification is mandatory.

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MANUAL LEFT UTERINE DISPLACEMENT

Current guidelines recommend:

Manual Left Uterine Displacement (LUD)

rather than placing the patient in a tilted position.

The patient remains supine while a provider manually displaces the uterus to the left.

Benefits include:

• Improved venous return
• Improved cardiac output
• Improved coronary perfusion pressure
• Better CPR quality

This intervention should be initiated whenever the uterus is at or above the level of the umbilicus (approximately 20 weeks gestation).

DOI: 10.1161/CIR.0000000000000300

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HIGH-QUALITY CPR

Current recommendations remain:

• Compression rate: 100–120/min
• Compression depth: 5–6 cm
• Full chest recoil
• Minimal interruptions
• Early defibrillation
• Team-based resuscitation

Pregnancy does not change these targets.

DOI: 10.1016/j.resuscitation.2021.02.009

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DEFIBRILLATION

Defibrillation is not contraindicated in pregnancy.

Energy levels are identical to those used in non-pregnant adults.

If ventricular fibrillation or pulseless ventricular tachycardia is present:

Defibrillate immediately.

There is no evidence supporting delay of defibrillation because of fetal concerns.

Maternal survival remains the highest priority.

DOI: 10.1161/CIR.0000000000000300

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ADVANCED AIRWAY MANAGEMENT

Pregnancy substantially increases the risk of:

• Difficult laryngoscopy
• Failed intubation
• Rapid desaturation
• Aspiration

The most experienced airway provider available should perform airway management.

Video laryngoscopy should be considered early when available.

DOI: 10.1097/AOG.0000000000004021

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MEDICATIONS DURING ACLS

Medication administration follows standard ACLS recommendations.

No dose reductions are recommended.

Drugs commonly used include:

• Epinephrine
• Amiodarone
• Lidocaine
• Magnesium sulfate (when indicated)

Maternal survival takes precedence.

DOI: 10.1161/CIR.0000000000000300

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POCUS DURING MATERNAL CARDIAC ARREST

Point-of-care ultrasound (POCUS) has become a critical component of modern maternal resuscitation.

Potential applications include:

• Identification of cardiac activity
• Detection of tamponade
• Assessment for massive pulmonary embolism
• Evaluation of hypovolemia
• Estimation of gestational age
• Identification of reversible causes

POCUS should never interrupt CPR.

DOI: 10.1007/s40140-022-00534-3

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THE FOUR-MINUTE RULE

One of the most important concepts in maternal resuscitation is the so-called:

Four-Minute Rule

If return of spontaneous circulation (ROSC) has not been achieved within four minutes of arrest in a pregnancy beyond approximately 20 weeks gestation:

Resuscitative hysterotomy should be initiated immediately.

The traditional goal is fetal delivery by five minutes after arrest.

DOI: 10.1016/j.ajog.2015.07.019

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RESUSCITATIVE HYSTEROTOMY

Modern evidence demonstrates that the primary purpose is:

Improvement of maternal resuscitation.

Benefits include:

• Relief of aortocaval compression
• Improved venous return
• Improved cardiac output
• Improved CPR effectiveness
• Increased likelihood of ROSC

It should be performed at the location of the arrest.

Transfer to an operating room should not delay intervention.

DOI: 10.1097/AOG.0000000000002462

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EXTRACORPOREAL CPR (ECPR) AND ECMO

Contemporary maternal resuscitation increasingly incorporates:

Veno-Arterial ECMO

and

Extracorporeal CPR (ECPR)

for carefully selected patients.

Young maternal age and potentially reversible causes make this population particularly suitable for advanced extracorporeal support in specialized centers.

DOI: 10.1016/j.resuscitation.2024.110771

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POST-ROSC MANAGEMENT

Successful resuscitation is only the beginning.

Post-ROSC priorities include:

• Hemodynamic optimization
• Oxygenation and ventilation control
• Neurological monitoring
• Continuous ECG monitoring
• Echocardiography
• Identification of arrest etiology
• Fetal assessment
• Intensive care admission

Maternal and fetal outcomes depend heavily on post-resuscitation care.

DOI: 10.1016/j.resuscitation.2021.02.012

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COMMON RESUSCITATION ERRORS

Frequent fatal mistakes include:

• Delayed CPR
• Failure to perform uterine displacement
• Delayed defibrillation
• Delayed airway management
• Waiting for fetal assessment before resuscitation
• Delayed resuscitative hysterotomy
• Unnecessary transfer to the operating room

Every delay reduces the probability of survival.

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OPERATIONAL CONCLUSIONS

Maternal cardiac arrest is among the most time-critical emergencies in medicine.

Three interventions consistently provide the greatest impact on survival:

1. High-quality CPR

2. Immediate manual left uterine displacement

3. Early resuscitative hysterotomy when ROSC is absent

The modern concept of maternal resuscitation recognizes that emptying the uterus is not solely an obstetric procedure.

It is often one of the most powerful resuscitative interventions available.

In many cases, the fastest way to save the fetus is to save the mother.

And the fastest way to save the mother may be to perform a resuscitative hysterotomy.

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KEY REFERENCES

Jeejeebhoy FM et al. Cardiac Arrest in Pregnancy. Circulation. 2015.
DOI: 10.1161/CIR.0000000000000300

American College of Obstetricians and Gynecologists (ACOG). Maternal Cardiac Arrest.
DOI: 10.1097/AOG.0000000000004021

Rose CH et al. From Perimortem Cesarean to Resuscitative Hysterotomy.
DOI: 10.1016/j.ajog.2015.07.019

ERC Guidelines Adult Basic Life Support.
DOI: 10.1016/j.resuscitation.2021.02.009

ERC Guidelines Post-Resuscitation Care.
DOI: 10.1016/j.resuscitation.2021.02.012

Perimortem Cesarean Delivery. StatPearls.

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DrRamonReyesMD
EMS Solutions International
International Scientific Review – 2026