Jesy Nelson is bravely sharing her journey with Twin-to-Twin Transfusion syndrome. In January, the former Little Mix singer ...

The amnion is the innermost layer of the placenta that surrounds the fetus. The amniotic sac is filled with fluid, which provides cushioning and protection. At the beginning of or during labor ...

The fertilized egg then splits into two or more embryos. Identical babies share a placenta, but each usually has a separate amniotic sac. Identical babies are the same sex and have the same blood type ...