Key Points Pregnancy may not be advisable for women with certain high-risk heart disorders (eg, pulmonary hypertension, coarctation of the aorta if uncorrected or accompanied by an aneurysm, Marfan syndrome with aortic root diameter of > 4.5 cm, severe symptomatic aortic stenosis, severe mitral stenosis, bicuspid aortic valve with ascending aorta > 50 mm, a single ventricle with impaired systolic function, cardiomyopathy, NYHA class III or IV heart failure).