A bilobed placenta (or bipartite placenta) is a variation in placental morphology and refers a placenta seperated into two near equal lobes. If more than two lobes are present it is termed a trilobed, four lobed and so on.
The estimated incidence is at up to ~4% of pregnancies.
It is thought to result from localized atrophy as result of poor dedicualisation or vascularization of a part fo the uterus (dynamic placentation theory) 5.
May be sonographically seen as two seprate placental discs of near equal size. The cord usually attaches to a thin connecting rim of chorionic tissue which bridges the two lobes. Less commonly the cord may insert into one of the lobes.
- it carries an increased incidence of type II vasa previa
- it may increase the incidence of postpartum hemorrhage due to retained placental tissue
If more than one lobe of placenta is seen in an antenatal scan consider: