A cervical check isn’t always comfortable, but it can help your doctor or midwife understand how your labor is progressing. During pregnancy and labor, you may hear terms like dilation, effacement, and station used to describe the changes happening in your body as you prepare for birth.
Understanding what those numbers mean, such as 2 centimeters dilated, 80% effaced, or -2 station, can help you feel more informed and less overwhelmed during labor. Here’s what each part of a cervical check measures and what it may tell you about labor progression.
Key Takeaways
- Cervical checks measure dilation, effacement, and station during labor
- Effacement describes how thin and soft the cervix becomes before birth
- Dilation measures how open the cervix is, from 0 to 10 centimeters
- Station refers to how far the baby has moved down into the pelvis
- Cervical checks can provide information about labor progress but cannot predict exactly when labor will happen or how long it will last
What Is Effacement?
Normally, before pregnancy and during the early months of pregnancy, your cervix is long and firm. It’s around 2 to 3 cm long. You may hear your provider say your cervix is effaced or wonder, “What does effaced mean?” Effacement (measured in percentage) means the cervix is thinning, softening, and shortening in preparation for labor. In late pregnancy or early labor, Braxton Hicks contractions start to shorten (efface) your cervix. Once your cervix has shortened to 1 cm, it’s 50% effaced. As you can see in the diagram above, it’s our goal to reach 100% effacement so there’s no cervix left.6
As most women discover toward the end of their pregnancy, effacement often begins before the expecting woman goes into labor. When your care provider performs a pelvic check, they may say your cervix is soft. Or they may even say a certain percentage of your cervix is effaced. It’s good to know that number. Your care provider will also state the dilation of your cervix at this time. Most people focus on the dilation number, but effacement is just as important. But first, what is dilation?7
What Is Dilation?
Once your cervix has effaced (thinned and softened), it begins to open, which is dilation. The cervix is the opening of the uterus, which is usually tightly shut. Braxton Hicks contractions can cause your cervix to dilate before active labor begins. This is why you sometimes hear about women being 3 cm dilated or dilated 3 centimeters but not yet in labor.
Some women may be 1 cm dilated for days or even weeks before labor begins. This is normal and just one small part of the cervical check. Or you could be on the other side of the spectrum, and your cervix can be firmly closed until you’re in active labor. Both experiences are entirely normal.
It’s not until regular contractions begin (when your contractions are at least five minutes apart, each is about one minute long, and that’s going on continuously for at least an hour) that your cervix will begin to open (dilate) more.8,9
As I stated, dilation tends to be the number people focus on the most because they know they must be 10 cm before pushing out their baby. While dilation is an important part of your cervical check, it isn’t the only factor that matters. Cervical ripening involves both softening and thinning of the cervix in addition to cervical dilation. So, paying attention to your entire cervical exam is important.6
For example, I’ve had clients in labor who were declared 5 cm dilated and 70% effaced, and then after two hours, they were rechecked and still 5 cm but 90% effaced. When that happens, people become frustrated because they’re still only 5 cm. However, they forget that their cervix is becoming thinner, which is necessary before it can reach 10 cm. Making progress from 70% to 90% is still good, so you shouldn’t feel discouraged!
Labor progression can vary significantly from person to person, which is why cervical checks only provide part of the picture during labor.
Related: Signs of Labor: How To Know When Baby Is Coming
When Is Labor Considered Active?
You may also be wondering when it’s considered active labor. The American College of Obstetrics and Gynecology (ACOG) states that 6 cm dilation is when you’re no longer in early labor and are now in active labor.1,2 At this time, your contractions will be noticeably longer, stronger, and closer together.2
How Providers Measure Cervical Dilation
Care providers measure dilation with their fingers.3 One finger inside your cervix is 1 cm, two fingers in your cervix are 2 cm, and they slowly start to spread their index finger and middle finger to continue to measure to 10 cm. This is why checking for dilation is subjective! Everyone has different-sized hands, so one person might think you are 7 cm while another claims you are 8 cm.
At 10 cm, your cervix is paper-thin (100% effaced), no cervix is left, and you’re fully dilated, which we call “complete.”3,7 For a better understanding, 10 cm is about the size of a softball or a baby’s head.
It’s common to hear people focus on being 10 cm dilated as the goal for delivery, but your cervix needs to thin and soften before full dilation can occur.
Related: When To Go to the Hospital in Labor
What Is Station?
Station describes how far your baby’s head has moved down into the pelvis during labor.
Most care providers won’t even say the baby’s station aloud during a cervical check. The “station” of a baby refers to the position of your baby’s head in relation to your pelvis. They record this as a number between -5 (minus five) and +5 (plus five). Zero station means the head is “engaged” on the cervix and has entered the vaginal canal within the pelvic bones. A negative number (-5 to 0) means your baby’s head isn’t engaged in the pelvis.6
During labor, it’s common for a baby to be at -3, -2, or -1. A positive number (0 to +4) means that your baby’s head is moving down the pelvis, and +5 means your baby is crowning (being born). Ideally, pushing begins once the head is engaged in the pelvis (at least 0 station), but waiting until the baby is lower can be even more helpful. This will help decrease your pushing time and reduce your chances of swelling.4
Is a Cervical Check Necessary?
I want all women to know you can refuse cervical checks. But the only two that you can’t get away from are:
- When you first arrive at the hospital to confirm labor progression
- When your provider checks whether you are fully dilated and ready to push
More cervical checks could lead to a slight risk of infection if your water has been broken, according to one study.5
Some providers may also perform membrane sweeps during a cervical exam near the end of pregnancy if requested or medically appropriate. Whether you get a cervical check or not, your body will know when it’s ready to have a baby!
What Cervical Checks Can and Cannot Tell You
During labor, it’s helpful to know if the baby is moving lower in the pelvis. If your care provider performs a cervical check, ask about your baby’s station. Knowing the effacement, dilation, and station gives you an overall idea of how much progress you’re making and how much more progress your body needs to make to give birth to your baby.
However, these do not indicate when you’re going into labor or how much longer your labor will last. A cervical exam provides information about the current moment in labor but cannot predict exactly when a baby will be born.
Every labor progresses differently. It can be reassuring to understand these numbers and the progress your body is making, but ultimately, they won’t benefit you or your baby beyond knowing where you stand in that moment.
I hope these descriptions help you better understand what the numbers mean and what your care provider is assessing during a cervical check.
Knowing what to expect can make the process feel less overwhelming. Here’s hoping your checks are quick and as comfortable as possible.
