Lobe placentaire accessoire: penser aux vaissaux praevia

We report the case of a 36-year old patient in her second pregnancy and hospitalization for metrorrhagia in the third trimester. Suprapubic ultrasound was performed during each hospitalization which showed anterior placenta in the correct location without signs of placental abruption. On her third hospitalization, at 36 weeks of pregnancy, transvaginal ultrasound was performed. It showed an echogenic structure similar to that of the placenta, located on the posterior surface of uterus, at 24 mm from the internal orifice of the cervix, evocative of accessory lobe of placenta. Color Doppler showed a vasa prævia connected to this lobe. Caesarean section was then scheduled at 37W giving birth to a healthy male baby weighing 3800g. Macroscopic examination of the placenta showed accessory lobe of placenta separated from the main disc of the placenta by membranes and connected to it by large vessels.