What is the recommended approach for detecting and managing heart disease in pregnant women, particularly those with a history of cardiovascular disease or risk factors such as hypertension, diabetes, or conditions like Marfan syndrome?

Heart Disease Detection in Pregnancy

All women with known or suspected cardiovascular disease of childbearing age must undergo pre-pregnancy risk assessment and counseling, and if already pregnant, evaluation should occur as early as possible with repeat assessments at regular intervals throughout gestation. 1

Initial Detection and Risk Stratification

Pre-Pregnancy or Early Pregnancy Evaluation

Every woman with cardiovascular disease or risk factors (hypertension, diabetes, Marfan syndrome) requires comprehensive cardiovascular assessment before conception or immediately upon pregnancy confirmation. 1, 2

The detection approach must include:

• Detailed personal and family history specifically targeting cardiomyopathies, Marfan syndrome, congenital heart disease, juvenile sudden death, long QT syndrome, catecholaminergic ventricular tachycardia, and Brugada syndrome, with explicit questioning about sudden deaths in family members 1

• Physical examination in left lateral recumbency assessing for new or changed murmurs, signs of heart failure, blood pressure measurement using standardized technique, and screening for proteinuria (especially with hypertension or pre-eclampsia history) 1

• 12-lead electrocardiogram to establish baseline, though recognize that pregnancy causes 15-20° left axis deviation and may show transient ST-T changes, Q waves in lead III, and inverted T waves in V1-V3 that can mimic structural disease 1, 3

• Transthoracic echocardiography as the single most important diagnostic tool, performed whenever dyspnoea occurs or a new pathological murmur is detected 1, 4, 3

• Oximetry in all patients with congenital heart disease 1

Condition-Specific Detection Protocols

For Marfan syndrome or known aortic disease:

• Imaging of the entire aorta (CT/MRI) must be performed before pregnancy 1
• Women with ascending aorta >45 mm require surgical treatment pre-pregnancy 1
• During pregnancy, repeated echocardiographic imaging every 4-8 weeks is mandatory for ascending aorta dilatation 1
• MRI without gadolinium is recommended for imaging distal ascending aorta, aortic arch, or descending aorta during pregnancy 1

For bicuspid aortic valve:

• Imaging of the ascending aorta is mandatory 1
• Surgical treatment pre-pregnancy should be considered when aortic diameter is >50mm or >27 mm/m² BSA 1

For Turner syndrome:

• Thoracic aortic diameters must be evaluated in relation to body surface area, as dissection may occur without dilatation 1
• Risk is highest with additional factors including bicuspid aortic valve, coarctation of aorta, and hypertension 1

For valvular heart disease:

• Stenotic lesions carry higher pregnancy risk than regurgitant lesions 1
• Moderate or severe mitral stenosis (valve area <1.5 cm²) requires monthly or bimonthly clinical and echocardiographic follow-up depending on haemodynamic tolerance 1
• Mild mitral stenosis requires evaluation every trimester and prior to delivery 1

Ongoing Monitoring During Pregnancy

High-risk patients must be managed in specialized centers with multidisciplinary teams including experienced cardiologists, obstetricians, and access to cardiothoracic surgery. 1, 2, 5

Surveillance Schedule

• Low-risk patients: At least one assessment during pregnancy, with echocardiography if any new or unexplained cardiovascular symptoms develop 2

• Patients with ascending aorta dilatation: Repeated echocardiographic imaging every 4-8 weeks 1

• Patients with moderate/severe mitral stenosis: Monthly or bimonthly clinical and echocardiographic follow-up 1

• Patients with known arrhythmia history: Holter monitoring for those with documented VT, atrial fibrillation, atrial flutter, or palpitation symptoms 1

Critical Warning Signs Requiring Immediate Evaluation

Echocardiography is indicated immediately when:

• Dyspnoea develops during pregnancy 1
• A new pathological murmur is detected 1
• Any new or unexplained cardiovascular symptoms appear 2
• Signs of heart failure emerge 1

Risk Classification Systems

Use the modified WHO classification system or CARPREG II risk score to stratify maternal cardiovascular risk, integrating lesion-specific and patient-specific information with clinical judgment. 3, 6

Absolute Contraindications to Pregnancy (WHO Class IV)

• Pulmonary arterial hypertension (mortality 17-50%) 1
• Severe systemic ventricular dysfunction 1
• History of or current type B aortic dissection 1
• Ehlers-Danlos syndrome type IV 1
• Eisenmenger syndrome 2, 7

High-Risk Conditions Requiring Specialized Management

• Marfan syndrome with ascending aorta 40-45 mm 1
• Moderate to severe mitral stenosis 1
• Severe aortic stenosis 1
• Mechanical valve prostheses (anticoagulation complications) 1

Genetic Counseling and Fetal Screening

Genetic counseling by a geneticist is highly recommended for patients with hereditary cardiac conditions, as offspring risk is significantly elevated compared to the 1% baseline population risk. 1

Genetic testing is particularly useful in:

• Cardiomyopathies and channelopathies (long QT syndromes) 1
• When other family members are affected 1
• Syndromes including Marfan, 22q11 deletion, Williams-Beuren, Alagille, Noonan, and Holt-Oram 1

All women with congenital heart disease should be offered:

• Fetal echocardiography at 19-22 weeks gestation 1
• Nuchal fold thickness measurement at 12-13 weeks (40% sensitivity for significant heart defects, 99% specificity) 1
• Chorionic villous biopsy at 12 weeks for genetic screening when applicable 1

Common Pitfalls to Avoid

• Never delay evaluation until symptoms develop in women with known structural heart disease, as decompensation can occur rapidly, particularly in the second and third trimesters 1

• Do not attribute dyspnoea or new murmurs solely to normal pregnancy changes without echocardiographic evaluation 1, 4

• Avoid radiation-based imaging when possible, but do not withhold necessary diagnostic procedures; radiation <50 mGy carries minimal fetal risk, and procedures should use fetal shielding 1

• Do not underestimate postpartum risk, as acute heart failure and thromboembolic events frequently occur during or immediately after delivery 1, 7

• Never assume prior cardiac surgery eliminates pregnancy risk; successfully repaired lesions still require assessment for residual defects and hemodynamic consequences 2