Fatal peripartum haemorrhage in a white-naped mangabey (Cercocebus lunulatus) associated with placenta previa

A 20-year-old zoo-born female gravid white-naped mangabey (Cercocebus lunulatus) was found dead adjacent to a pool of blood. The uterus contained one female fetus in breech malposition that was developed to term. The cervix was fully dilated and fetal membranes had ruptured indicating early parturition. The placenta was located ventrally within the posterior uterus and fully blocked the os cervix. It showed multiple areas of acute haemorrhage, and was considered the source of fatal peripartum maternal haemorrhage. These findings are consistent with a diagnosis of placenta previa, an abnormal implantation of the placenta in the lower uterine segment in humans and other primates. Risk factors reported in humans, which were also present in this monkey, include pluriparity, increased maternal age and the possibility of dystocia during previous pregnancies. To our knowledge, this is the first report of placenta previa in mangabeys.