[Auscultation of the heart in pregnancy (author's transl)].

During pregnancy a third heart sound is perceptible in 80% of women and a fourth in 16%. Functional systolic heart sounds are found in over 90% of pregnant women, and diastolic sounds in 18%. The amplitude of a functional heart sound usually increases after inhalation of amyl nitrate. Mitral stenosis, aortic stenosis, tricuspid and pulmonary sounds are accentuated during pregnancy. Sounds of mitral and aortic insufficiency become less or even inaudible during pregnancy.