What is the recommended management for hypertrophic cardiomyopathy (HCM) during delivery and postpartum?

Management of Hypertrophic Cardiomyopathy at Delivery and Postpartum

Scheduled vaginal delivery is the recommended first-choice delivery method for most women with HCM, with continuous cardiac monitoring during labor and extended postpartum observation for 24-48 hours due to fluid shift-related pulmonary edema risk. 1

Delivery Management

Mode of Delivery

• Vaginal delivery should be the default approach for most patients with HCM, as cesarean section carries higher bleeding rates and similar adverse outcomes (3-4%) compared to vaginal delivery 1
• Cesarean section should be reserved exclusively for obstetric indications or emergency maternal health reasons, not for cardiac reasons alone 1
• Valsalva maneuver during labor is well tolerated and does not require avoidance 1
• Assisted vaginal delivery (forceps, vacuum) can be used when needed to minimize maternal exertion 2

Intrapartum Monitoring

• Continuous heart rate and rhythm monitoring is essential during delivery for patients at high risk of arrhythmias 1
• Pulse oximetry and continuous ECG monitoring should be maintained throughout labor 3
• Hemodynamic monitoring intensity should be tailored to disease severity (WHO Class II vs III risk stratification) 1

Medication Management During Delivery

β-Blockers (preferably metoprolol):

• Continue throughout labor and delivery in all patients already on therapy 1
• Do not discontinue peripartum, as this increases arrhythmia risk 1
• Monitor neonate for bradycardia and hypoglycemia after delivery 1

Oxytocin administration:

• Administer ONLY as a slow infusion at rates <2 U/min (approximately 33 mU/min) to avoid hypotension and tachycardia 1, 3
• Never give as rapid IV bolus, which can cause severe hypotension and uterine hyperstimulation 3

Avoid methylergonovine in the postpartum period due to >10% risk of vasoconstriction and hypertension 3

Anesthesia Considerations

• Neuraxial anesthesia (epidural or spinal) is safe and reasonable for both vaginal and cesarean delivery 1, 2
• Take precautions to avoid hypotension during anesthesia administration 1
• General anesthesia is not contraindicated but neuraxial techniques are preferred 1, 2
• No hemodynamic instability directly related to neuraxial anesthesia has been documented in case series 2

Postpartum Management

Critical Monitoring Period

• Mandatory clinical observation for 24-48 hours postpartum due to increased risk of pulmonary edema from fluid shifts 1
• This extended monitoring period is non-negotiable regardless of delivery mode 1
• Continue hemodynamic monitoring throughout this period 3

Postpartum Complications to Monitor

• Pulmonary edema (most common serious complication) 1
• Congestive heart failure (occurs in approximately 13% of cases) 2
• Arrhythmias, particularly atrial fibrillation 1
• Postpartum hemorrhage (documented in 13% of cases) 2

Medication Continuation

• Continue β-blockers postpartum without interruption 1
• β-blockers are generally safe during breastfeeding (metoprolol preferred) 1
• Judicious use of diuretics may be required for dyspnea symptoms 4

Anticoagulation Management

• For patients with atrial fibrillation, therapeutic anticoagulation is mandatory regardless of CHA2DS2-VASc score 1, 5
• Transition from pregnancy anticoagulation (LMWH or warfarin) to appropriate postpartum regimen 1
• Pregnancy is a hypercoagulable state that persists into early postpartum period 5

Risk Stratification and Outcomes

Overall Prognosis

• Maternal mortality is very low, with only 3 sudden deaths reported in literature over 17 years, all in high-risk or undiagnosed patients 1
• Overall morbidity rate is approximately 26% 2
• Symptoms or complications occur in approximately 25% of pregnant women with HCM, most of whom had pre-existing symptoms 1

High-Risk Features Requiring Intensified Monitoring

• Severe left ventricular outflow tract obstruction (LVOTO) 1, 6
• Symptomatic status prior to pregnancy 1, 6
• Moderate to severe systolic LV dysfunction 1
• Recurrent arrhythmias despite optimal medication 1

Critical Pitfalls to Avoid

• Never administer oxytocin as a rapid bolus - this is the most common preventable error 1, 3
• Do not discontinue β-blockers peripartum due to concerns about neonatal effects - maternal safety takes priority 1
• Do not assume cesarean section is safer than vaginal delivery - evidence shows equivalent or worse outcomes 1
• Do not discharge patients before 24 hours postpartum - fluid shifts peak during this period 1
• Do not use atenolol if initiating β-blocker therapy - use metoprolol, bisoprolol, labetalol, or propranolol instead 1, 7
• Mavacamten is absolutely contraindicated during pregnancy and postpartum if breastfeeding due to teratogenic effects 1

Multidisciplinary Team Coordination

• Care should be coordinated between cardiology and obstetrics throughout delivery and postpartum period 1
• For high-risk patients (WHO Class III-IV), consultation with maternal-fetal medicine specialists is advised 1
• A delivery plan should ideally be established by the end of the second trimester 1