What substances are exchanged by a mother and baby?

During pregnancy, a mother and baby exchange various substances primarily through the placenta. Oxygen and nutrients, such as glucose and amino acids, are transferred from the mother to the fetus, while waste products like carbon dioxide and urea are sent from the fetus to the mother for elimination. Additionally, antibodies from the mother can pass to the baby, providing immune protection. Hormones and other signaling molecules may also be exchanged, influencing fetal development.