Corrigendum to Histology Atlas of the Developing Mouse Placenta.

Figure 45. Example of twinning with a fused placenta at E15.5. A, Gross image of twin embryos sharing a fused placenta. The embryo shown on the right is slightly smaller and paler than its counterpart on the left. B, Low magnification of twin embryos sharing a fused placenta supporting two sets of umbilical arteries (UA). C, Higher magnification of fused placenta and separate uterine arteries with a clear border (arrows) between the two placentas where there is junctional zone fusion. Note the disorganization of the placenta associated with the right embryo. Intertwin growth discrepancy is a common finding and is likely due to differential nutrient exchange, oxygen supply, and waste removal within the respective placentas.