The Amazing Placenta

Please enjoy this anatomy lesson on the placenta, brought to you from information found at my.cleavelandclinic.org

What is the placenta?

The placenta is a temporary organ that connects your baby to your uterus during pregnancy. The placenta develops shortly after conception and attaches to the wall of your uterus. Your baby is connected to the placenta by the umbilical cord. Together, the placenta and umbilical cord act as your baby's lifeline while in the womb. Functions of the placenta include:

• Provides your baby with oxygen and nutrients.

• Removes harmful waste and carbon dioxide from your baby.

• Produces hormones that help your baby grow.

• Passes immunity from you to your baby.

• Helps protect your baby.

When does the placenta form?

The placenta begins to form after a fertilized egg implants in your uterus around seven to 10 days after conception. It continues to grow throughout your pregnancy to support your baby. The placenta starts as a few cells and grows to be several inches long.

When does the placenta take over?

The placenta takes over hormone production by the end of the first trimester (12 weeks of pregnancy). Up until this time, the corpus luteum handles most of the hormone production. Many people's first-trimester symptoms of nausea and fatigue go away once the placenta takes over in the second trimester.

Where does the placenta form?

The placenta can form anywhere in your uterus. It develops wherever the fertilized egg implants into your uterine wall. Some of the positions of the placenta are:

• Posterior placenta: The placenta grows on the back wall of your uterus.

• Anterior placenta: The placenta grows on the front wall of your uterus closest to your abdomen.

• Fundal placenta: The placenta grows at the top of your uterus.

• Lateral placenta: The placenta grows on the right or left wall of your uterus.

The placenta can move up until about 32 weeks of pregnancy. It's common to have a placenta that moves upwards and away from your cervix as your baby gets bigger.

What does the placenta look like?

The placenta looks like a disc of bumpy tissue rich in blood vessels, making it appear dark red at term. Most of the mature placental tissue is made up of blood vessels. They connect with the baby through the umbilical cord and branch throughout the placenta disc like the limbs of a tree.

What color is the placenta?

The placenta has two sides: the side attached to your uterus and the side closest to your baby. The side attached to your uterine wall is a deep reddish blue color, while the side facing your baby is gray.

How big is a normal placenta?

The placenta is about 10 inches long and 1 inch thick at its center. It weighs around 16 ounces (1 pound) by the time your baby is born.

What is the placenta made of?

The placenta begins to develop when the fertilized egg implants into your uterine wall. The placenta contains mostly blood vessels contained within structures called “villi.” The blood vessels connect with the baby’s bloodstream through the umbilical cord. The rest of the placental tissues mainly connect the villi to the umbilical cord and allow your blood to bathe the villi, supplying the baby with oxygen and nutrients.