Cardiac disease is a significant cause of illness and death during pregnancy, complicating about 1–4% of pregnancies globally.

Pregnancy and associated heart disease are vast topics. This article will present an overview and highlight some salient aspects of cardiac anomalies and their management.

Physiological Changes in Pregnancy:

During pregnancy, there are many changes to the mother’s physiology. The physiological changes of pregnancy are

• Increase Blood volume by ~40-50%
• Increase Cardiac output: by ~30-50% (peaks by mid-pregnancy)
• Decrease Systemic vascular resistance
• Increase Heart rate: ~10-20 bpm
• Hypercoagulable state

These physiological changes of pregnancy can unmask previously undiagnosed heart disease or worsen pre-existing conditions.

Types of Cardiac Disease in Pregnancy

1. Pregnancy and hypertension

Hypertension in pregnancy is a major cause of maternal and fetal morbidity and mortality. Serious maternal complications like pre-eclampsia, eclampsia (seizure-like disorder), can lead to stroke, end-organ damage and even maternal death and fetal complications like low birth weight, IUGR, preterm birth, etc.

2. Congenital Heart Disease

Unrepaired congenital heart disease during pregnancy can lead to acute heart failure. Eisenmenger’s syndrome and uncorrected cyanotic CHD are contraindications for pregnancy. Many women with repaired congenital heart disease can have successful pregnancies, but the risk depends on the specific defect and repair status.

3. Cardiomyopathies

Peripartum cardiomyopathy (PPCM) is a form of heart failure that develops in the last month of pregnancy or within five months postpartum, with no other identifiable cause. PPCM is associated with significant maternal morbidity and mortality, especially if the left ventricular ejection fraction is severely reduced.

4. Valvular Heart Disease

Valvular heart diseases can increase the risk of pregnancy complications. Stenotic lesions (e.g., mitral or aortic stenosis) are particularly dangerous due to the increased blood volume and cardiac output of pregnancy. Regurgitant lesions (MR/AR) are generally well tolerated.

5. Ischemic Heart Disease

IHD is rare in pregnancy, but its prevalence increases with maternal age and comorbidities.

6. Arrhythmias

Pregnancy can increase the risk of arrhythmias (irregular heartbeats), especially in women with underlying structural heart disease. Hemodynamically significant arrhythmias require prompt management during pregnancy.

High-Risk Cardiac Conditions

Sometimes pregnancy is contraindicated or generally nonadvisable due to high-risk cardiac anomalies. These are:

• Pulmonary arterial hypertension (PAH) is a rare, progressive disorder characterised by high blood pressure specifically in the pulmonary arteries that carry blood from the right side of the heart to the lungs (including Eisenmenger syndrome)
• Marfan syndrome (a genetic disorder that affects the body’s connective tissue) with aortic root dilation (> 45 mm)
• Severe aortic or mitral stenosis
• Severe left ventricular dysfunction (ejection fraction <30%)
• Mechanical heart valve, uncorrected cyanotic heart disease
• Uncorrected coarctation of the aorta or associated aneurysm

Management Principles

• Preconception Counselling: Essential for women with known heart disease to assess risks and plan management.
• Multidisciplinary Care: Involvement of cardiology, maternal-fetal medicine, anesthesiology, and neonatology is recommended, ideally in a tertiary care center.
• Monitoring: Close surveillance throughout pregnancy, with particular attention during periods of maximal hemodynamic stress (late second trimester, third trimester, labour, and postpartum).
• Medication Management: Drug dose adjustments may be needed during pregnancy, considering maternal and fetal safety.
• Delivery Planning: Vaginal delivery is often preferred, but cesarean may be indicated for specific cardiac conditions ( e.g. severe AS, coarctation of aorta etc.). Hemodynamic monitoring during labour is critical. Delivery is often planned in the early term, and epidural anaesthesia is preferred to reduce the stress response. Close monitoring for 72 hrs. after delivery is required for such cases.

Citations:

• https://www.ahajournals.org/doi/10.1161/CIR.0000000000000772
• https://www.msdmanuals.com/professional/gynecology-and-obstetrics/pregnancy-complicated-by-disease/heart-disease-in-pregnancy
• https://my.clevelandclinic.org/health/diseases/17068-heart-disease–pregnancy
• https://www.ncbi.nlm.nih.gov/books/NBK537261/