Cervical Effacement: What is it and how to measure (2024)
What we’ll cover in this post:
If you are someone who has used a “fertility awareness” method or “natural family planning/NFP” to either prevent a pregnancy or try to conceive (TTC), you may be familiar with your cervix.
Tracking your cervical position, texture, and cervical mucus can give you some insight about when you’re in the fertile window of your cycle. These cervical changes, along with some other subtle bodily changes, can point to signs and symptoms of ovulation.
Knowing what your cervix is doing is not only helpful when you’re trying to conceive, but it also provides valuable information during pregnancy, labor, and birth.
If you are pregnant, toward the end of your pregnancy and/or throughout labor, you may consent to have your cervix examined. When a provider is checking a cervix in regards to labor, they are assessing for cervical effacement and dilation.
So, what does this mean?
What is a cervix?
To keep things simple, upon entry into the vaginal canal, before you reach the uterus (where the baby is) there’s a cervix. The cervix is a donut shaped organ that forms a passageway between the vagina and the uterus. When you’re not pregnant, the cervix helps to ensure that “foreign” objects, like tampons, menstrual cups, and bath/pool water don’t end up floating around in your uterus. When you are pregnant, your cervix still possesses those protective measures, while also staying closed in order to keep the baby in.
Toward the end of your pregnancy, as your body starts preparing to birth your baby, your cervix will change. These changes include cervical effacement and cervical dilation.
When your healthcare provider or your labor nurse assess your cervix for effacement and dilation, it may give them a better idea of where you are within the labor process.
What does Cervical Effacement mean?
Cervical effacement refers to the thickness (or thinness) of the cervix. Other terms that can be interchangeable with cervical effacement include: shortening, softening, or ripening. Throughout the duration of pregnancy, your cervix remains thick and firm. Once you are getting closer to labor, your cervix may start to get thinner, or efface.
Cervical effacement is measured in a percentage. So, when you hear your provider tell you about their cervical assessment, you may hear them say “you’re 80% effaced.” This means they can only feel about 20% of your cervix; the remaining 80% has completely thinned out.
When does cervical effacement happen?
Cervical effacement will usually begin happening at some point toward the end of your pregnancy. It will happen either before cervical dilation, or alongside cervical dilation.
Cervical effacement must occur before you can push your baby out.
It’s important to keep in mind that a cervix can change very quickly. Sometimes, pregnant folks choose to decline cervical exams because they can be uncomfortable, there are some risks involved, and they can be disappointing. For instance, you can have a cervical exam and be 1cm dilated and 10% effaced, just to end up pushing 2 hours later. It’s a pretty subjective assessment and may or may not help to predict how near or far birth is.
On the other hand, some pregnant folks prefer to have cervical exams throughout labor. Sometimes, knowing your cervix is making, even subtle, changes, can be motivating.
If you would prefer to not have any cervical exams throughout your labor, this may be something you want to add to your birth plan!
Cervical Effacement versus Dilation
While cervical effacement refers to the thinness of the cervix, cervical dilation refers to how open the cervix is.
Sometimes, cervical effacement and dilation occur simultaneously, other times, your cervix may be fully effaced before it starts to dilate. Both cervical effacement and dilation must occur prior to pushing out your baby.
While cervical effacement is measured in a percentage, cervical dilation is measured in centimeters. Your cervix will go from 0 centimeters, meaning completely closed, to 10 centimeters, meaning you are ready to push your baby out. It is common, for instance, to go from 1cm to 4cm pretty quickly, but then remain at 4cm for hours. This is your body’s way of preparing for birth.
Every labor and every cervix is different. Some pregnant folks will progress very quickly all the way through, some will make fast progress and then slow down, and others will just have slower progress for the entirety of labor; all versions are a variation of normal.
Cervical Effacement Symptoms
Every person and every pregnancy is different, so you may or may not experience symptoms related to cervical effacement. If you do experience symptoms related to effacement, you may notice:
Some mild cramping/contractions
Loss of your mucus plug (looks like snot, might be tinged with pink or brownish blood)
Increase in vaginal discharge
Feeling that your baby has “dropped” or feels lower in your pelvis
Since cervical effacement and dilation tend to occur simultaneously, it’s not uncommon to experience some subtle symptoms while this is happening. Your cervix may begin to change days/weeks before you go into labor. This is why some pregnant folks may lose their mucus plug days/weeks prior to going into labor.
How to Measure Cervical Effacement
Cervical effacement is measured during a vaginal/cervical examination. Your provider will use gloved fingers to feel your cervix. When feeling for effacement, they are feeling for the thinness or thickness of your cervix. As labor progresses, the cervix will become thinner and it will dilate (open).
It is possible for pregnant people to feel their cervix themselves, but if you are not familiar with the cervix and recognizing cervical changes, it may be difficult to notice any cervical changes without the help of an experienced provider.
Bishop Score
The Bishop Score, also referred to as a Pelvic Score, is a common method used to calculate a number that helps to help determine the “readiness” of the cervix. This is typically used prior to an induction. It can also be used to help predict the likelihood of labor happening soon.
The Bishop Score looks at:
Dilation
Effacement
Station - Station refers to the position of the baby's head in relation to the pelvis. Once the baby’s head begins to leave the bony prominences of the pelvis, the numbers become positive (+1, +2, +3).
Consistency - This refers to the consistency of the cervix. The closer someone is to labor, the softer the cervix becomes. The cervix is sometimes described as “mushy” as labor progresses and birth approaches.
Position - This refers to whether the cervix is anterior, mid, or posterior in relation to the baby’s head and pregnant person’s pelvis.
The Bishop Score provides a numbered score between 0 and 13. Anything above an 8 indicates that the cervix is favorable for a vaginal delivery and/or an induction. Anything above a 10 typically indicates that labor/birth is near.
The Takeaway
Toward the end of your pregnancy, your cervix will start to change in preparation for labor and the birth of your baby. These changes include: cervical effacement and cervical dilation. Cervical effacement refers to the thinness or thickness of the cervix, whereas cervical dilation refers to the openness of the cervix. Prior to pushing out your baby, your cervix must be 100% effaced and 10 centimeters dilated.
If you choose to have your cervix examined toward the end of your pregnancy and throughout labor, your healthcare provider and/or labor nurses can help to give you “play by plays” as far as your cervical changes. Some pregnant folks really thrive off of knowing about these cervical changes, while others may become disappointed by a “lack of progress” or, what seems like, slower progress than what they were hoping for.
It’s important to remember that it is your decision whether you choose to have your cervix examined or not. It’s also important to keep in mind that, just like any other procedure, there are risks and benefits that come with cervical examinations.
You can read all about the pros, cons, and evidence in regards to cervical examinations over at Motherboard. Once you feel confident in your decision, you can add your choice to your birth plan so everyone on your birth team is on board.
As always, if you have any questions or concerns, never hesitate to reach out to your healthcare provider.
🤍 The Motherboard Team
