Exploring the Wonderful World of Placentas
Hey there, fellow birth enthusiasts! Today, we are diving into a topic that might not get as much attention as it deserves but plays a HUGE role in pregnancy: the placenta. Did you know that you are growing an entire ORGAN in addition to the tiny human you are growing? This magical, often underrated organ is your baby’s lifeline during pregnancy, providing oxygen, nutrients, and even hormones to keep things moving smoothly. There is a lot of variety in the world of placentas including stuff about the placenta, as well as where your placenta is located. Let’s break it down.
1. The Standard Placenta: Discoid Placenta
First up is the most common type, known as the discoid placenta. Picture a pancake or a flattened disc—this is what most placentas look like. In this form, the placenta attaches to one side of the uterine wall, with the umbilical cord sprouting from the center. It's the typical design and what most of us envision when we think "placenta." (Are you also thinking “placenta” a lot?) It’s efficient and does its job well!
2. Bilobed Placenta
Next, we have the bilobed placenta. Imagine your pancake, but this time it’s in two halves, like two mini pancakes connected by a bridge of tissue. This means the placenta has two main lobes. It’s a little different from the standard placenta but can still function just fine in most cases. However, sometimes a bilobed placenta can lead to challenges, like an increased risk of bleeding after birth, so it’s something that might get extra attention from your provider.
3. Succenturiate Placenta
Now, here’s a fun word for you: succenturiate placenta. This is when there’s an extra little lobe attached to the main placenta, like an extra, cute little satellite organ! It’s a bit like having a mini sidekick. The main concern here is making sure that after birth, all the pieces of the placenta are delivered—if that extra lobe stays behind, it could lead to postpartum complications like infection or bleeding or even affect the hormonal cascade that brings in your milk for breastfeeding.
4. Circumvallate Placenta
The circumvallate placenta has a distinct appearance, with a raised, thicker edge. It looks like the placenta is curled or rolled up around the sides, forming a kind of border. This type can sometimes cause complications like restricted growth or preterm birth, so it’s another one that providers like to keep a close eye on. But don’t worry—if you have one of these, your care team will have a plan to monitor and support you!
5. Marginal Cord Insertion
Now let's talk about marginal cord insertion. In most pregnancies, the umbilical cord attaches right in the middle of the placenta, like a button in the center of a pillow. But with marginal cord insertion, the cord attaches at the edge of the placenta instead. While this can sometimes cause issues with nutrient flow, leading to growth restrictions, most of the time, babies with marginal cord insertion grow just fine with proper monitoring. Your healthcare provider will likely keep an eye on your baby’s growth throughout your pregnancy to make sure everything is on track.
6. Placenta Previa
Now we are moving away from the shape of the placenta and getting in to WHERE the placenta is hanging out in your uterus: placenta previa. In placenta previa, the placenta covers part or all of the cervix, the opening that the baby will eventually pass through. This can be tricky because as the pregnancy progresses, that placement can lead to bleeding and might necessitate a C-section. But the good news is that, in many cases, the placenta can "migrate" upward as the uterus grows, moving out of the way by the time you’re ready to give birth. Always remember to ask lots of questions to your providers!
7. Anterior vs. Posterior Placenta
Another aspect to consider is whether your placenta is anterior or posterior. This refers to where the placenta attaches inside your uterus—either at the front (anterior) or the back (posterior). An anterior placenta might make it a bit harder to feel your baby’s movements early on, since it's like having a cushion between the baby and your belly. This also makes “kick counts” a little silly- you won’t be able to feel things as well with an anterior placenta and it’s an easy way to freak yourself out. A posterior placenta, on the other hand, attaches to the back wall of the uterus, which can make baby kicks more noticeable earlier in pregnancy because you can feel the little kicks through your abdominal muscles.
Neither is better or worse—they’re just different positions, each with its own experience.
8. Placenta Accreta, Increta, and Percreta
These next three—placenta accreta, increta, and percreta—are variations of a condition where the placenta attaches too deeply into the uterine wall. Normally, the placenta separates from the uterus after the baby is born, but in these cases, the placenta can be stubborn and stay stuck. The difference between these three comes down to how deeply the placenta invades:
Accreta: The placenta attaches too firmly but stays in the superficial layers of the uterus.
Increta: The placenta invades deeper into the muscle layer of the uterus.
Percreta: The placenta invades all the way through the uterine wall and may attach to other organs like the bladder.
This is a serious condition that often requires surgical intervention, but with proper medical care, outcomes are improving all the time.
The Bottom Line
No matter what type of placenta you have, remember that it’s doing an incredible job supporting your baby’s growth and development. Different types of placentas may require different management, but with the help of your care team, you’ll have the support you need for a safe and healthy pregnancy.
So, next time someone mentions the placenta, you'll know there’s a whole world of variety hidden in that amazing, life-sustaining organ! And if you ever find yourself with one of these less common placental situations, know that you’re in good company and that modern medicine has your back.
Until next time, stay curious and keep celebrating the wonder of birth!
Love,
Emily
Williams Obstetrics by F. Gary Cunningham, et al.: A comprehensive textbook widely used by obstetricians that covers various aspects of pregnancy, including placental anatomy and abnormalities.
Also used in the creation of this post: knowledge acquired in my physical therapy education and work in the neonatal ICU.
