Foods that can be eaten include: meat, hard cheese, tofu, eggs, butter and vegetables with no starch. Some foods that are NOT allowed include: cereal, pasta, milk, breads and other sugars. If you are scheduled in the late afternoon and can eat breakfast before the scan, it must be a low carbohydrate diet as well.
The placenta (also known as afterbirth) is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, thermo-regulation, waste elimination, and gas exchange via the mother's blood supply; fight against internal infection; and produce hormones to support pregnancy.
Quick Answer. John Hopkins Medicine states that the amniotic sac, the fluid-filled sac that holds the fetus in the uterus, functions to protect the unborn baby and help regulate the baby's temperature. The amniotic fluid inside the sac cushions the fetus and protects the fetus from damage.