In a study of 471 344 Danish women published online September 21, 2018 in JAMA Network Open, mothers of infants born with a major congenital anomaly had a 15% increased risk of acute myocardial infarction, coronary revascularization, or stroke compared with women without an affected infant. This elevated risk rose to 37% among women who gave birth to more severely affected infants with multiorgan congenital anomalies.