A succenturiate placenta is an abnormality in placental morphology where there is one or more accessory lobes that may be connected to the main part of the placenta by blood vessels. This smaller, separate placenta is of similar echotexture to the main portion of the placenta.
The likelihood of this abnormality occurring is estimated at about two per 1,000 pregnancies. Succenturiate placentas can be identified in prenatal ultrasounds.
The main portion of the placenta is connected to the umbilical cord while the succenturiate placenta, if connected to the main portion at all, is connected by blood vessels. Any connections can be identified during an antenatal ultrasound.
The main risks of this type of placenta occur at the time of birth and don't increase the risk of fetal anomolies. Prenatal recognition of this type of placenta is important because connecting blood vessels can rupture during delivery and can cause fetal death. Other complications of a succenturiate placenta can include an increased risk of type two vasa previa and an increased risk of postpartum hemorrhage.
Sometimes, the term bilobate placenta is used to describe a placenta with one or more accessory lobes that are more equal in size than in a succenturiate placenta. In other cases, it is possible that a contraction can simulate a succenturiate lobe but it usually disappears within 30 minutes or less.