Interstitial Implantation of the Placenta presenting with Retained Placenta after Vaginal Delivery at Term

We report an unusual case of an interstitially-implanted pregnancy presenting with retained placenta after normal vaginal delivery of a live fetus at term. A 32 year-old primigravida, with no previous uterine surgery or instrumentation underwent induction of labour at term for suspected intrauterine growth retardation. The placenta was retained after normal vaginal delivery. Manual removal of the placenta under anaesthesia was attempted but unsuccessful. Exploratory laparotomy and hysterotomy were performed for removal of the placenta, which was found to be implanted in the right cornual region of the uterus. This part of the uterus was sacculated, thinned out and poorly-contracted after the removal of the placenta, resulting in postpartum hemorrhage necessitating uterotonics, compression sutures and placement of a B-lynch suture. This case highlights the need to consider abnormal implantation sites when the placenta is retained in a low risk patient.