Incidence of mitral valve prolapse in one hundred clinically stable newborn baby girls: an echocardiographic study.

Clinical and echocardiographic examinations were performed on 100 clinically stable, newborn baby girls. Mitral valve prolapse was noted on the echocardiograms of seven babies. Three subjects had systolic clicks, two of whom had systolic murmurs following the click. The four other babies who had echocardiographic evidence of mitral valve prolapse had no abnormal auscultatory signs. Of the 93 babies without evidence of mitral prolapse, 91 had normal echocardiograms and auscultatory features; one was noted to have a murmur consistent with a ventricular septal defect, and another had an eccentric aortic valve on the echocardiogram which was suggestive of a bicuspid aortic valve. Serial studies on our group of subjects will yield useful information regarding the natural history of mitral valve prolapse.