Thus, the villi are part of the border between maternal and fetal blood during pregnancy.

The fetal blood is tested for signs of anemia and other blood problems.

A sample of fetal blood can be taken from the umbilical vein prior to the transfusion.

The mother's blood and fetal blood usually don't mix in the placenta.

Animal placentas are classified based on the number of tissues separating the maternal from the fetal blood.

The fluid around the fetus or the fetal blood can be tested for infection.

Those tests look directly for the toxoplasmosis parasite in amniotic fluid and fetal blood.

As a result, fetal blood in the placenta is able to take oxygen from maternal blood.

The fetal blood, on the other hand, is first in the child's body, then in the villi, and then returns to the child again.

Nevertheless, fetal blood from cows (roughly $40 to $50 a quart) remains an important tool for the development of drugs and medical research.