These twins share one placenta and one amniotic sac, and are the rarest type of twins, with only one in five twin pregnancies falling into this category. As the twins share everything, it means ...

Twins share everything from their in-utero environment ... no two twins are exactly the same. These conditions make every identical twin pair a mini-experiment. Close attention has been paid ...

So in a sense, while they're sharing a womb, they're not having to share everything ... Women's Hospital in Boston.) "These siblings tend to do really well!" she says. Twins do seem to enjoy ...