'at risk' heart disease requiring special care and expert.

Generic Risk Factors for women with congenital heart disease during pregnancy:

• poor cardiac function before pregnancy (New York Heart Association functional classification > II) or cyanosis
• impairment of systemic ventricular function (ejection fraction < 40%)
• left heart obstruction (mitral valve area < 2 cm2, aortic valve area < 1.5 cm2, left ventricular outflow tract peak blood pressure gradient (measured by Doppler ultrasonography) > 30 mm Hg before pregnancy)
• preconception history of adverse cardiac events such as symptomatic arrhythmia, stroke, transient ischaemic attack, and pulmonary oedema

The expected cardiac event rate in pregnancies with 0, 1, or > 1 of these risk factors is 5%, 27%, and 75%, respectively (1)

A review (1) has defined lesions as low risk, moderate risk and high risk

Low Risk:

• ventricular septal defects; atrial septal defects (unoperated), coarctation (repaired); tetralogy of fallot

Moderate Risk:

• mitral stenosis; aortic stenosis; systemic right ventrical; cyanotic lesions without pulmonary hypertension; Fontan-type circulation

High Risk:

• Marfan's syndrome; Eisenmenger syndrome; other pulmonary arterial hypertension

Reference:

1. Uebing A et al. Pregnancy and congenital heart disease. BMJ 2006; 332:401-6.
2. British Heart Foundation (1/2000). Factfile