Prenatal ductal constriction and closure usually are related to maternal intake of prostaglandin receptor inhibitors during late gestation but may occur spontaneously. This report describes three live-born infants sharing echocardiographic features of spontaneous intrauterine ductal constriction, closure, or both, although only one had a prenatal diagnosis. Interestingly, in addition to severely hypertrophied right ventricles, all three had hyperechogenic tricuspid valve papillary muscles. Two also had mild ascending aorta dilation. These cases raise mechanistic questions because of intrauterine ductal occlusion, bright papillary muscles, and potential dilated ascending aortas.