How does an unborn child receive food while in the womb? --- Capt, Raigarh, India
Marshall Brain Answers:
A baby gets all of his food, as well as his oxygen and water, from its mother's bloodstream. The baby's waste products (like C02) are disposed of in the mother's blood stream as well. It is a two-step process. In the placenta, the mothers blood flows in to a network of blood vessels and capillaries. Molecules in the mother's blood like glucose, proteins, fats, oxygen, etc. flow out of the mother's blood supply and are absorbed into another network of blood vessels and capillaries containing the baby's blood supply. The baby's blood then flows through the umbilical cord back to the baby.
So when the mother eats a hamburger or a banana, the molecules of glucose, proteins, fats, vitamins, etc. are absorbed into the mother's blood stream by her small intestine. The molecules flow to the placenta, are transfered to the baby's bloodstream and flow to the baby through the umbilical cord.
More details on the placenta the transfer of molecules:
Note that this same feeding process puts the baby at risk whenever the mother introduces anything into her bloodstream that would be bad for the baby. This includes alcohol, drugs, toxins from cigarettes, etc.