What is the purpose of the placenta during pregnancy?

The placenta serves a crucial role during pregnancy, primarily functioning to provide oxygen and nutrients to the developing fetus. It is a specialized organ that forms during pregnancy and connects the mother to the fetus through the umbilical cord. The placenta allows for the exchange of gases, nutrients, and waste products between maternal and fetal blood, although the two blood supplies do not mix directly. Oxygen and essential nutrients like glucose are transported from the mother to the fetus, supporting its growth and development.

In contrast, while the placenta does have a role in nutrient transfer, it does not actively develop maternal blood vessels, nor does it act as a barrier to all substances; certain substances can cross the placental barrier, including some pathogens and drugs. The placenta also does not primarily store waste products; instead, it facilitates the removal of fetal waste products back into the mother's circulatory system for excretion. Therefore, the primary purpose of the placenta is to ensure that the fetus receives the necessary oxygen and nutrients for its development, making this choice the correct one.