Background After an aeroplane crash, recovery of the ‘black box’ is a high priority for investigators; analysis of recorded parameters frequently identifies cause or contributing factors. The placenta likewise provides an invaluable record of the pre-‘crash’ period in hypoxic ischaemic encephalopathy (HIE); its examination often identifies significant factors such as inflammation or vasculopathy.

Objective To determine the frequency of histopathologic placental examination and chorioamnionitis in a high-risk population of encephalopathic newborns.

Methods We studied neonates ≥36 weeks’ gestation admitted with HIE to three tertiary-level UK centres between 01/07/06 and 30/06/11. We assessed if placental histopathological examination was carried out and if there was evidence of chorioamnionitis and/or funisitis.

Results 305 infants were admitted with HIE in the 5-year study period. Placental data were unavailable for 140 outborn infants. Only 50/165 (30%) inborn babies had placentas submitted to pathology. Histopathological examination confirmed chorioamnionitis and/or funisitis in 16/50 (32%) cases.

Conclusion Placental examination serves several vital roles in babies born with suspected HIE: it defines pathophysiology, provides important prognostic information regarding future neurodevelopmental outcome, and shows mitigating factors of medicolegal relevance to causation of brain injury. Intrapartum infection and chorioamnionitis are associated with poor neonatal outcomes including cerebral palsy. Only 30% placentas were examined in our tertiary centres, yet those examinations showed a high incidence of chorioamnionitis. The low rate of placentas being submitted for examination in neonates born depressed, coupled with the high incidence of proven chorioamnionitis in those submitted, is of great concern.