It is a generally held concept that finding increased aspirated amniotic fluid squames at autopsy supports a diagnosis of acute fetal asphyxia, the massive aspiration of squames being an indicator of terminal gasping. To evaluate this concept, we identified autopsies on 15 third-trimester stillborns with clinical acute placental abruption (acute asphyxia); 13 also had thymic petechiae and none had severe acute thymic involution, findings also supporting acute asphyxia. Thirty third-trimester stillborns with findings supporting a subacute or chronic mode of death, including severe thymic involution and absence of thymic petechiae, comprised the comparison group. Intra-alveolar squames were scored as 0, no squames; 1+, scattered squames singly or in small groups; and 2+, squames in many alveoli, at least focally in compacted clusters. In all cases, the squames were patchily distributed, and none received a score of 0. In the abruption group, the intra-alveolar squames were scored as 1+ in 12 (80%) and as 2+ in 3 (20%) cases, while in the comparison group, the squames were scored as 1+ in 20 (67%) and 2+ in 10 (33%) cases (P = NS). There was also no difference in the quantification of intra-alveolar squames in term compared to preterm stillborns. In conclusion, quantification of intra-alveolar squames did not aid in separating an acute mode of death (acute asphyxia) from subacute or chronic modes of death.
Keywords: asphyxia; autopsy; fetal demise; intra-alveolar squames; stillbirth; third trimester.