The function of the amnion is to protect an embryo as it develops in the womb. Also known as the amniotic membrane, it fills with fluid to form a protective sac over the embryo.
The amniotic membrane contains stem cells that can develop into multiple cell types found in the body. Amnion cells are frequently used to reconstruct damaged skin in the head and neck area. Ophthalmic surgeons use amniotic membrane transplantation as an alternative to corneal and conjunctival reconstruction. Oncologists also use amniotic membrane cells to halt the delivery of oxygen and nutrients to cancer cells, thereby preventing the cancer from growing and spreading throughout the body.