Review of Autopsies of Stillborn Infants with Retroplacental Hematoma or Hemorrhage

Abstract

Intrathoracic petechiae are a potential marker of acute asphyxia in stillborn infants. Retroplacental hematoma (RPH) is a cause of acute asphyxia. The histological features of RPH can be timed using criteria for intrauterine duration of fetal death. Autopsies of stillborn infants of >26 weeks in gestation with RPH were evaluated for gross or microscopic evidence of petechiae. Placental gross and microscopic features were recorded. Eleven controls from other mechanisms of death were randomly selected. Intrathoracic petechiae were present in all 17 infants with RPH of >50% of the placental area, in 3 of 7 infants with <50% area RPH, and in 2 of 11 infants with other diagnoses. The placenta demonstrated basal plate neutrophils in all cases of RPH ( N = 21). Early coagulation necrosis in the villi overlying the RPH was present in 5 of 13 cases after 4 to 24 hours, and complete coagulation necrosis was present in 3 of 4 cases after 24 hours. Infants with RPH underlying >50% of the placenta demonstrate intrathoracic petechiae, but controls and infants with smaller RPH do so much less frequently. This is consistent with the hypothesis that intrathoracic petechiae are a marker for intrauterine asphyxia. Basal plate neutrophils are a useful early marker of retroplacental hemorrhage. Early coagulation necrosis of the placenta over RPH begins in 4 to 24 hours but is not complete after more than 24 hours.