Immunohistochemical detection of myocardial necrosis in stillbirth and neonatal death.

The aims of this study were to determine whether immunohistochemical staining for C9 can demonstrate myocardial necrosis in the fetus and neonate. Hearts from cases of stillbirth or neonatal death with confirmed myocardial necrosis (in neonates) or with ischemic lesions outside the heart (in neonates and stillborns) were stained immunohistochemically with antibodies to C9. All five cases with confirmed myocardial infarction showed positive immunohistochemical staining for C9, largely localized to the infarcted areas. The youngest subject was born at 24 weeks gestation and died at 4 days of age. One of two neonates without myocardial necrosis on H&E staining but with pathological evidence of ischemic lesions elsewhere showed staining of scattered fibers. Six out of ten hearts from macerated stillborn infants showed varying degrees of positive staining. Immunohistochemical staining for C9 detects myocardial necrosis in neonates of a gestational age of 24 weeks or more. C9 is also demonstrable immunohistochemically in macerated stillborns, and this is likely to represent myocardial necrosis. The method is of great potential value in the investigation of cardiac ischemia in the fetal and perinatal period.