Cardiac arrest in pregnancy is a rare but devastating emergency, demanding rapid, coordinated intervention. While the general principles of cardiopulmonary resuscitation (CPR) remain the same, cardiac arrest in pregnancy introduces unique anatomical and physiological considerations that can complicate both diagnosis and management. For obstetricians, anesthesiologists, intensivists, and emergency physicians, understanding these nuances is essential to improve maternal and neonatal survival.

Epidemiology and Significance

The incidence of cardiac arrest in pregnancy is estimated at 1 in 20,000 to 50,000 pregnancies, varying by region and healthcare setting. Despite its rarity, it is associated with high maternal and perinatal mortality. Survival depends heavily on early recognition, high-quality resuscitation, and timely perimortem cesarean delivery.

Causes of Cardiac Arrest in Pregnancy

A useful mnemonic is BEAU-CHOPS, which highlights both obstetric and non-obstetric causes of cardiac arrest in pregnancy:

B – Bleeding: Obstetric hemorrhage due to uterine rupture, placenta previa, placental abruption, or postpartum hemorrhage.
E – Embolism: Amniotic fluid embolism, pulmonary embolism, or air embolism.
A – Anesthetic complications: High spinal anesthesia, local anesthetic systemic toxicity, aspiration, or difficult airway.
U – Uterine atony: Severe hemorrhage following delivery.
C – Cardiac disease: Congenital heart disease, valvular lesions, peripartum cardiomyopathy, ischemic heart disease.
H – Hypertension: Severe preeclampsia/eclampsia, intracranial hemorrhage, or stroke.
O – Other causes: Trauma, sepsis, electrolyte imbalance, or drug overdose.
P – Pulmonary pathology: Severe asthma, ARDS, or pneumonia.
S – Sepsis: Rapidly progressing septic shock from chorioamnionitis, pyelonephritis, or systemic infection.

Physiological Challenges in Resuscitation

Pregnancy alters maternal physiology in ways that complicate cardiac arrest in pregnancy management:

• Aortocaval Compression: From 20 weeks onward, the gravid uterus compresses the inferior vena cava and aorta, reducing venous return and cardiac output when supine.

• Respiratory Changes: Increased oxygen consumption and decreased functional residual capacity result in rapid desaturation during apnea.

• Airway Edema: Difficult intubation risk is higher; smaller endotracheal tubes are often required.

• Cardiovascular Load: Blood volume increases by up to 40–50%, but this reserve is quickly depleted with hemorrhage.

• Dual Lives at Stake: Maternal resuscitation is the primary goal, but fetal viability influences urgency and decision-making.

Management of Cardiac Arrest in Pregnancy

1. Immediate Basic Life Support

• High-quality chest compressions at the standard rate and depth.

• Manual left uterine displacement (LUD) or 15–30° tilt to relieve aortocaval compression.

• Activate obstetric and anesthesia teams without delay.

2. Advanced Life Support

• Airway: Early intubation with smaller ETT (6.0–6.5 mm). Anticipate difficult airway.

• Breathing: Provide 100% oxygen; avoid hyperventilation.

• Circulation: Defibrillation and drug doses are unchanged. Establish IV/IO access above the diaphragm to ensure drug delivery.

3. Perimortem Cesarean Delivery (PMCS)
If ROSC (Return of Spontaneous Circulation) is not achieved within 4 minutes, proceed to emergency cesarean.

• Goal: delivery by 5 minutes post-arrest (“4-minute rule”).

Benefits of PMCS in Cardiac Arrest in Pregnancy:

• Relieves aortocaval compression, improving maternal hemodynamics.

• Enhances the chance of neonatal survival.

• Should be initiated at the site of arrest, not delayed for transfer to OT.

4. Post-Resuscitation Care

• Maternal stabilization in ICU with a multidisciplinary team.

• Identify and treat the underlying cause (hemorrhage control, thrombolysis for PE, antihypertensives for eclampsia, etc.).

• Fetal monitoring if pregnancy continues.