Identical Twins Pregnancy
It's harder to tell with an identical twins pregnancy, though. Some identical twin babies will have their own placentas, but some will share, depending on when the fertilized egg split. If the egg split within the first three days, the twin babies will have their own placenta and membranes. If the egg splits between the fourth and ninth days, the twins will share a placenta and a chorion (the outer membrane), but have two amnions (the inner membrane). These can be called either diamniotic or monochorionic.