Ischemic changes in fetal myocardium. An autopsy series

It has been assumed that fetal myocardial necrosis is an uncommon event that occurs only under unusual circumstances. We studied random heart sections on 76 fetal and perinatal autopsies from a 4-year period to determine the types and frequency of histologic abnormalities that occur in fetal myocardium. Vacuolar degeneration was extremely common (43% of stillbirths, 84% of live births) but a nonspecific finding. Ischemic changes, which are typically associated with coagulation necrosis, myofiber waviness, or contraction band necrosis, were seen in 21% of stillbirths and 32% of live births. In the majority of cases with histologic evidence of ischemic change, a combination of either contraction band necrosis, coagulation necrosis, and/or myofiber waviness was identified. Only rarely was any one of the abnormalities seen as an isolated feature. In only two autopsies were the ischemic changes identified in the initial autopsy report. We conclude that the histologic changes associated with ischemia that may represent myocardial necrosis are not uncommon and are frequently overlooked at autopsy.