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What Is the Connection between the Placenta and Umbilical Cord?

Marlene Garcia
Marlene Garcia

The placenta and umbilical cord act as the fetal supply line during the nine months a baby develops in the uterus. These organs function to provide oxygen-rich blood and nutrients to the fetus and remove waste products. Both structures are considered the lifeline during pregnancy to keep a fetus alive until birth.

Both the placenta and the umbilical cord grow as the fetus matures. The placenta attaches inside the uterus and produces estrogen, progesterone, and human chronic gonadotropin, hormones that promote growth and protect the fetus from infection. Near the end of pregnancy, antibodies are formed, which reach the fetus via the placenta and umbilical cord. These antibodies protect the newborn baby for the first three months of life.

An umbilical cord connects a fetus to the placenta.
An umbilical cord connects a fetus to the placenta.

The link between the placenta and umbilical cord consists of three blood vessels, two arteries, and a vein. The umbilical cord carries blood from the placenta to the fetus to provide oxygen. Arteries transport carbon dioxide waste from the fetus to the mother’s blood supply, where it is filtered and removed by her kidneys. This process prevents the baby’s blood and mother’s blood from mixing, begins about five weeks after conception, and continues until delivery. The placenta and umbilical cord act as fetal lungs, kidneys, and digestive systems during pregnancy.

Identical twins typically share a placenta, but have separate umbilical cords.
Identical twins typically share a placenta, but have separate umbilical cords.

As the baby grows inside the amniotic sac, a cavity filled with warm fluid to protect the fetus from harm, the umbilical cord and placenta grow to accommodate needs of the fetus. The umbilical cord allows the fetus to move freely inside the uterus as a form of exercise to build muscle. Identical twins typically share a placenta, but have separate umbilical cords. Non-identical twins develop with separate placentas and cords. Studies show after a woman's first pregnancy, the placenta and umbilical cord increase in size in subsequent pregnancies.

An umbilical cord is a thick, blood-rich cord that connects a baby to its mother during the gestation process.
An umbilical cord is a thick, blood-rich cord that connects a baby to its mother during the gestation process.

During the birth process, the umbilical cord continues to send oxygen to the fetus. After the baby is delivered, the cord is clamped near the baby’s navel and cut, severing the connection between the placenta and umbilical cord. This occurs after the baby begins breathing, allowing him or her to receive vital oxygen through the lungs. The placenta remains inside the uterus for a short time before it is expelled through the vaginal opening.

The placenta produces hormones like progesterone.
The placenta produces hormones like progesterone.

Most doctors advise against using alcohol, tobacco and certain medications during pregnancy because these substances might pass from the placenta to the fetus via the umbilical cord. Several conditions might develop during pregnancy that restricts the flow of blood from the placenta, including cords that become knotted or wrapped around the baby’s neck. Ultrasound examinations commonly identify these problems, which might lead to caesarean birth instead of vaginal delivery as a precaution.

Discussion Comments

Lostnfound

The placenta is amazing all by itself! I know that when it's delivered, the doctor checks to make sure it's all in once piece, and that none of it has been retained inside the uterus.

I've heard of one really bizarre trend where women have their placentas dried, ground up and put into capsules and then they take the capsules like medicine. This is just a little too weird for me. I'm not sure what it's supposed to accomplish.

When I was a senior in high school, we had a unit on pregnancy and childbirth in my independent living class. Two nurses came in and they had these models of fetuses. Essentially, they were lifelike baby dolls. The full term fetus was attached to a placenta, which was a wad of pink plastic -- looked like bubble gum. The umbilical cord was pink rubber tubing. The girls were fascinated. The boys were completely grossed out. We thought it was hilarious.

Grivusangel

The umbilical cord is the supply line, and that term is used in every field where a supply line is needed. Start listening for it. You hear it all the time, if you just become aware of it.

It's completely amazing to me how all of this works. Most of the time, the cord stays where it's supposed to, and the baby is born, having been supplied for nine months by three veins and an artery. It truly is a miracle every time. It shouldn't work that way every time, but it does.

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    • An umbilical cord connects a fetus to the placenta.
      By: lanamaster
      An umbilical cord connects a fetus to the placenta.
    • Identical twins typically share a placenta, but have separate umbilical cords.
      By: Svetlana Fedoseeva
      Identical twins typically share a placenta, but have separate umbilical cords.
    • An umbilical cord is a thick, blood-rich cord that connects a baby to its mother during the gestation process.
      By: massimo maghenzani
      An umbilical cord is a thick, blood-rich cord that connects a baby to its mother during the gestation process.
    • The placenta produces hormones like progesterone.
      By: logos2012
      The placenta produces hormones like progesterone.
    • The placenta develops inside of the uterus during pregnancy.
      By: ProMotion
      The placenta develops inside of the uterus during pregnancy.
    • Delivery of the placenta typically occurs about 15 to 30 minutes after birth.
      By: arztsamui
      Delivery of the placenta typically occurs about 15 to 30 minutes after birth.
    • The entirety of the placenta must be removed from the uterus following the birth of a child.
      By: WONG SZE FEI
      The entirety of the placenta must be removed from the uterus following the birth of a child.
    • Ultrasound examinations during pregnancy help monitor umbilical cord placement.
      By: JackF
      Ultrasound examinations during pregnancy help monitor umbilical cord placement.
    • A newborn's umbilical cord contains stem cells that might be used to treat blood diseases or immune system disorders.
      By: cantor pannatto
      A newborn's umbilical cord contains stem cells that might be used to treat blood diseases or immune system disorders.