Placenta praevia percreta

Abstract

Placenta percreta and praevia are rare and life-threatening causes of massive maternal haemorrhage. The incidence of concurrent placenta percreta and praevia has increased over recent years with the rising number of caesarean sections. Placenta praevia, defined as the ‘implantation of the placenta in the lower uterine cavity, completely or partially covering the internal os’, is the major risk factor for placenta accreta spectrum (PAS) in women with prior caesarean section. PAS is the abnormal adhesion of the placenta to the uterine wall and consists of three types; placenta accreta, increta and percreta. Placenta percreta represents only 5% of cases of PAS but has the highest maternal morbidity and mortality of the three types and involves invasion of the placenta through the entirety of the myometrium, potentially into neighbouring organs. We present a case of placenta praevia percreta and review the macroscopic and microscopic findings pertinent to making the diagnosis.