Glossary of Labor and Birth Terms

Tiles pelling out the words Labor Terms

I was inspired to write this post after reading this one by a labor and delivery nurse. Her list is 80% medical intervention terms, and I wanted to show a different perspective on “basic labor”. I don’t think “basic labor” involves Pitocin, IV, epidural or induction. So without further ado, here’s MY take on basic labor vocabulary expectant parents need to know:

Uterus: The organ that is the star of the show when it comes to pregnancy, labor and delivery! It is a sac shaped muscle that the baby grows in until it is ready for birth. Penny Simkin says that the uterus at term is the largest and strongest muscle in a woman’s body. Over the course of pregnancy it grows from the size and shape of an upside down pear to the size of a watermelon. It practices for labor by tightening and relaxing to build strength. Sometimes that process is called “Braxton-Hicks” after the two doctors who described it first in a book and (as doctors tend to do) named it after themselves.

Contraction: Since the uterus is a muscle, its job is to contract. Just like other muscles in your body! There are a couple of important differences, though. First, it’s not one under voluntary control. If it were, people would not be so eager for labor to begin, they could just do it! It works more like the muscles in your heart and intestines — automatically as needed. Second, since it is sac shaped, the muscle contractions work to change its own shape and to move the baby.

Cervix: The part of the uterus that changes the most during the birth process. It’s at the bottom of the uterus just under the baby’s head. (usually!) As the upper part of the uterus pulls on it with contractions, it thins until it is paper thin and then is stretched open to allow the baby through and out.

Vagina/Birth Canal: This is NOT the external genitals. (Which means “Vajazzling” isn’t actually done on the vagina. Thank goodness for that! I was so confused when I first heard of it.) The vagina or birth canal is the tunnel like opening between the outside of the body and the cervix. The walls of the vagina have a lot of give to allow a baby to pass through and then return to normal afterwards. Did you know that *technically* it’s a “vagina” when you’re not pregnant, but conception magically changes it into the “birth canal”? Nothing actually changes, and most people don’t pay any attention to the distinction, because it is the SAME THING. Most people (including myself) use the terms interchangeably.

Perineum: The stretchy skin between the opening of the vagina and the anus. It also has amazing power to accommodate the birth and return to normal.

Effacement: When the cervix gets thinner during labor. It doesn’t vanish into thin air, it gets pulled up into the main body of the uterus, so it is no longer in front of the baby’s head.

Dilation: The process of opening the cervix so the baby can come through. During pregnancy, the opening in the cervix can feel like a dimple. But by about the time the urge to push comes, it has stretched enough for the baby’s head to pass through. The books say that’s about 10 cm, but it might be slightly more or less depending on the size of baby’s head.

Station: About halfway through the inside of the pelvis as the baby passes down through it, there are some small bumps in the bone where muscles attach. These are called the “ischial spines” and they are the marker for figuring out the baby’s progress in passing through the pelvis. When the top of the baby’s head is even with that spot, that’s called a “zero station.” If the baby’s head is above or below that point, they make an estimate of how many centimeters higher or lower it is. Above that spot would be a negative number. Most babies are at a -2 station when labor begins, meaning the head is estimated to be 2 cm above those bumps in the bone. When the baby’s head stays visible at the opening of the birth canal, that’s generally about a +3 station. I remember that it is a positive thing when baby comes out, so the positive numbers are when baby is closer to birth.

Labor Progress: Far, far too many people think that this is a synonym for “dilation” – it is not! Dilation is one way to make progress, but so are effacement, descending to a different station, and rotating to a good position to pass through the pelvis! Getting fixated on dilation means you can miss the other progress you are making, so always keep a broad view of what it means to make progress in labor.

First Stage of Labor: The first stage of labor is the part where the body’s focus is on changing the cervix from being thick and closed to hold the baby in to being thin and open enough so that the baby can pass through. It’s all about staying relaxed enough that her uterus can just do its thing. There are several parts to the first stage: Prelabor, Early Labor, Active Labor, and Transition.

Prelabor: Some people call this false labor. Those people are meanies! Some people will feel stronger contractions periodically as they approach the birth of their baby. Sometimes those contractions stick around for a couple of hours before fading away. Those contractions are very real! They often help prepare the body for labor and can even cause some effacement and dilation. Nothing false about that! I prefer to use the term “prelabor” or “warmup labor” for moms who experience it.

Early Labor: Sometimes it’s hard to tell prelabor from early labor. They’re very similar. Pretty mildish contractions, sometimes not even regular yet. Generally it’s possible to talk through them, but they can be annoyingly hard to sleep through or focus on anything else.

Active Labor: There’s not usually any dramatic shift into active labor. Over time, the contractions become longer, stronger and closer together. Doctors used to say that active labor began at 4 cm. And then last year a bunch of doctors sat around and voted to change it so that now “they” say it starts at 6 cm. It’s a really arbitrary thing. However, there were so many exceptions that I stopped thinking of it in terms of dilation at all. In my own personal definition, active labor begins when regular contractions are strong enough that they can’t talk during them and instead needs to listen to their body and move, sway, breathe, whatever they need to do to work with their body. So basically, when the laboring person needs to be active in working through her labor.

Transition: As the cervix gets close to being completely thin and out of the way, the body basically goes into a flat out sprint to the finish. Only instead of running, this sprint is the uterus contracting longer, stronger and even more closely together than in active labor. It can be pretty intense as the body is working very powerfully! Just remember than your labor is never going to be stronger than you, because it IS you!

Second Stage of Labor: The second stage is all about moving the baby down and out. Unlike the first stage, in this part of labor you can actively help the process along. Most (but not all) birthing parents will feel a strong urge to push, and if they engage their voluntary muscles to work with the uterus, it can help bring the baby down and out. This stage of labor ends with the baby emerging.

Third Stage of Labor After the baby is born, the body births the placenta. Because it’s smaller and softer, this stage of labor is shorter and usually less intense. The uterus contracts, the placenta separates from the inner surface of the uterus, and the placenta comes out.

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