The Amazing Placenta: Placental Physiology

The placenta is an organ that grows inside the uterus during pregnancy that, through the umbilical cord, links the baby to the mother’s bloodstream in order to supply nutrients and oxygen to the growing fetus.

Unlike any other organ in the human body, placentas have a temporary lifespan and exist only for the purpose of growing a baby. Arteries in the mother’s uterus pool at the placental attachment site, becoming loose and vein-like in that they do not continue to constrict like other arteries. This pooling blood bathes the placental membranes, where, without mixing the two blood supplies, nutrients and oxygen are transported into fetal circulation.

The placenta also produces hormones that support the pregnancy, and filters wastes such as carbon dioxide out of the baby’s bloodstream. The placenta serves as a barrier to many toxins for the baby, preventing many harmful substances from reaching the baby. The placenta does not filter all chemicals, however, and substances like alcohol and some prescription drugs can reach the baby.

By the end of pregnancy, the placenta is a large, thick organ, about the size of a salad plate. Within a few minutes of the birth, the mother’s body sheds the placenta and it, too, is born. The mother’s uterus then clamps down, pinching off the loose arteries.

If you wish to view your placenta after the birth, ask your care provider to show it to you, if for no other reason than for educational or anatomical learning. If you birth in a hospital, it will likely be thrown away shortly after the birth, unless you exercise your right to keep it.

Many parents are not informed about the uses and interesting traditions surrounding placentas. Village Herbals offers placenta encapsulation, art prints, placenta tincture, and other options.

Many thanks to Jessica “Veege” Ruediger for her contributions to this page.