The most serious lesion a woman may have, as far as pregnancy is concerned, is mitral stenosis. An increased abdnominal pressure interferes with her lung capacity, and her lungs are already overcongested. The left ventricle may be small with mitral stenosis, and therefore her general systemic circulation poor. For those two reasons mitral stenosis should absolutely prohibit pregnancy. While many women with well compensated valvular disease go through pregnancy without serious trouble, still, as stated above, they should be advised never to marry. If they do marry, or if the lesion develops after marriage, warning should be given of the seriousness of pregnancies. If a woman becomes pregnant while there are symptoms or signs of broken compensation, there can be no question, medically or morally, of the advisability of evacuating the uterus. The same ruling is true if during pregnancy the heart fails, compensation is broken, and the usual symptoms of such heart weakness develop, provided a period of rest in bed, with proper treatment, has shown that the heart will not again compensate. Under such a condition delay should not be too long, as the heart may become permanently disabled. If, during pregnancy in a patient with a damaged heart, albuminuria develops and the blood pressure is increased, showing kidney insufficiency, there can be no question of delay, from every point of view, and labor must be precipitated; the uterus must be emptied to save the mother's life. If a pregnant woman is known to have a degenerative condition of the myocardium, or arteriosclerosis, the danger from the pregnancy is serious, and the pregnancy should rarely be allowed to continue. Even if no serious symptoms occur during the term of the pregnancy, and the heart continues to compensate sufficiently for its defect, labor should never be allowed to be prolonged. The tension thrown on the heart during labor is always severe, and has not infrequently caused acute heart failure by causing acute dilatation, and in these damaged hearts tediousness and severe, intense exertion should not be allowed. Proper anesthetics and proper instrumentation should be inaugurated early. Patients who have successfully passed through the danger of pregnancy with cardiac lesions, possibly relieved by radical treatments, should be warned against ever again becoming pregnant. If this warning does not prevent future pregnancies, the family physician and his consultant must decide just what it is proper to do. It is to be understood that no uterus should ever be emptied until one or more consultants have approved of such treatment. Sometimes serious heart weakness develops during the later weeks of pregnancy, requiring the patient to remain in bed and receive every advantage which rest, proper care and well judged medicinal treatment will give the circulation.