The Placenta
The Placenta is the lifeline for the baby when the baby is inside the uterus and growing.
It is the organ that we grow ourselves to support the growth and development of the baby. It is an AMAZING organ.
We want our placenta functioning optimally to ensure the exchange of nutrients and waste products between us and the baby.
The placenta has more functions than just providing “food and oxygen” to the baby. The Placenta:
- removes carbon dioxide and waste from the baby
- provides protection from infection diseases
- releases hormones into both bloodstreams that affect the pregnancy and baby
- its role in function changes as the baby grows bigger and has higher metabolic needs.
Third Stage of Labor
During the third stage of labor is when the Placenta is “born” because its job is done!
This can range from a few minutes to 30mins on average. Most providers consider a placenta to be retained when it has not detached and delivered by 30 mins after the baby was born.
There are two types of management styles for the third stage of labor, Active and Expectant.
More hospitals use active management as the routine practice. Where you may see more expectant management in out of hospital settings but either setting can do both options depending on risk factors.
For example being if you are low risk for hemorrhage in a hospital you can opt for expectant management and if you’re high risk at an out-of-hospital setting you can opt for more of an active management.
Active Management
Active management is where they are more involved to encourage the placenta to detach from the uterine wall and be born. This involves early cord clamping, cord traction, and prophylactic (preventative) uterotonic medication such as pitocin. Pitocin is the first line option used and recommended by governing bodies and research. It can be given IV or IM, both have been shown to be effective at reducing the risk of PPH.
Expectant Management
Expectant management is waiting for the placenta to give us signs that it has detached and ready to be born. The signs we are looking for are gush of blood, lengthening of the cord, change in the shape of the uterus and it rises up in the abdomen, and sometimes pressure in the perineum maybe with an urge to push. Each management style has its risks and benefits.
Placenta Attachment
Sometimes there are abnormalities in the attachment of the placenta into the uterus. There are 4 main abnormalities with attachment of the placenta, and one is the placement of it. Placenta Previa is an abnormality of the placement of the placenta in the uterus. With the attachment abnormalities, there are 3 different degrees and they are known as Placenta Accreta, Percreta, and Increta. Normally the uterus attaches to a layer of the uterus that sheds at delivery, but sometimes it can attach too deep into the uterus. These can all occur independently, or sometimes both Previa and an attachment abnormality is present. These are commonly found during pregnancy on ultrasound, and depending on how deeply the placenta is embedded, it may lead to a hysterectomy.
Placenta Previa
Previa is when the placenta is covering, partially or fully, the cervical os. If this is present at term, a c-section is recommended. Sometimes a low-lying placenta is grouped in with placenta Previa, but they are different. Low-lying is just a placenta that is close to the cervical os, but not covering. They will likely watch it closely to ensure it does not move to cover the cervical os, but vaginal birth is still an option.
Placenta Accreta
Placenta Accreta is when the placenta attaches too deeply into the uterine wall. Placenta Increta is when the placenta attaches into the uterine muscle.
Placenta Increta
Placenta Increta is when the placenta attaches into the uterine muscle.
Placenta Percreta
Placenta percreta is when the placenta embeds completely through the uterine wall, sometimes attaching to nearby organs.
Placenta Inspection
Once the placenta is delivered the provider will usually inspect the placenta. They are ensuring that it is fully intact and looking if there are any abnormal characteristics about the placenta. They want to ensure it is intact because if there are pieces missing they are likely still inside the uterus, and this can lead to issues like a postpartum hemorrhage. The size of the placenta is another thing they look at, on average placentas are around 8.5 inches wide. So they look to see if it’s around that size or smaller or larger.
The placenta has two sides when you look at it on the outside of the uterus. The “maternal” side and the fetal side.
"Dirty Duncan"
The “maternal” side is the side that was embedded into the uterine wall. This side is known as “Dirty Duncan” because of its maroon red color with a ragged appearance. This side is made up of 15-20 little transfer units called cotyledons. These units are where nutrients, oxygen, and waste transfer occurred. When the provider is checking to see if the placenta is fully intact, they are ensuring that all of these cotyledons are present. When inspecting these cotyledons they also look for calcifications on the placenta, which are white spots on the placenta that are hard and have a grainy feel to them. These are signs that the placenta was starting to age and may not have worked as optimally.
"Shiny Schultz"
The fetal side is known as “Shiny Schultz” because of its smooth, shiny, and almost translucent appearance. This is the side that the baby was living on and where the umbilical cord inserts into the uterus. This is the prettier side, where you can see the vessels coming out from the umbilical cord insertion site that makes it look like a tree of life. This is also what is covered by the amniotic sac. I always like to lift the amniotic sac up around this side to show parents where the baby was living!
Umbilical Cord Insertion
When looking at the fetal side of the placenta, the provider will look at where and how the cord is inserted into the placenta, is it central, eccentric, marginal, or velamentous? Central and Eccentric are the normal insertion sites and are the most common. Central is in the middle of the placental and eccentric is off center but greater than 2 cm from the edge of the placenta. Marginal and Velamentous are considered abnormal insertion types and are closely watched during pregnancy, but can be missed sometimes.
Abnormal Umbilical Cord Insertions
Marginal is when the umbilical cord inserts on the edge of the placenta, but the umbilical vessels still inserts into the placental mass.
Velamentous is when the cord inserts on the edge of the placenta and the vessels first attach to other membranes before entering the placenta, so a portion of the umbilical vessels are exposed and not protected by the wharton’s jelly. This increases the risk of injury to those vessels because they are exposed, which is what makes this type of insertion abnormal and higher risk. Especially when it is paired with what is called vasa previa, which is where the umbilical vessels are covering or near the cervical os. So this increases the risk for injury to those vessels. The injury to these vessels can cause life-threatening bleeding for the baby or compression of these exposed vessels can stop the flow of oxygen to the baby. This can be found prenatally and usually c-section at ~35 weeks is recommended because if not found the risk of stillbirth is high when both velamentous and vasa previa are present.
Umbilical Cord
Velamentous is when the cord inserts on the edge of the placenta and the vessels first attach to other membranes before entering the placenta, so a portion of the umbilical vessels are exposed and not protected by the wharton’s jelly. This increases the risk of injury to those vessels because they are exposed, which is what makes this type of insertion abnormal and higher risk.
True Knot in Cord
Especially when it is paired with what is called vasa previa, which is where the umbilical vessels are covering or near the cervical os. So this increases the risk for injury to those vessels. The injury to these vessels can cause life-threatening bleeding for the baby or compression of these exposed vessels can stop the flow of oxygen to the baby. This can be found prenatally and usually c-section at ~35 weeks is recommended because if not found the risk of stillbirth is high when both velamentous and vasa previa are present.
Amazing Organ...but also the reason for rest!
The placenta is an amazing organ, it does so much for babies during our pregnancies. It’s also the only organ that we grow ourselves outside of the womb from scratch. I never remember to really inspect my placenta at my own deliveries, but I always ask families if they want to see their placenta after delivery. Then explaining all the pieces of the placenta is fun!
Also, knowing that the placenta is 8.5 inches wide on average is important for postpartum because that is the size of the wound in your uterus. So resting when you are postpartum is so important because that wound needs to heal!
If you had an 8-inch wound on the outside of your body you would not try to clean the house or go on long walks, you would rest!
