Cervical effacement is a term to describe thinning of the cervix, the lower end of your uterus that connects with your vagina. This thinning occurs before and during labor and helps prepare your cervix for delivery.
If you’re nearing the end of your pregnancy, congrats! And if you’re getting a little antsy, we know the feeling. Pregnancy is long.
You might be wondering what signs you’ll experience as you get closer to delivery. When you hear the word labor, you probably think about contractions and how the cervix has to dilate enough to allow your baby to pass through the vagina. But effacement is another important part of the equation — it just doesn’t always get as much attention.
Here’s more about effacement throughout late pregnancy and labor, how it’s measured, and how long the process might take.
Related: 8 ways to naturally induce labor
Effacement refers to the thinning of the cervix during labor. It’s also described as a softening, shortening, or even “ripening.” (Yeah, we don’t love that term, either.)
In pregnancy, the cervix is usually between 3.5 and 4 centimeters long. As you near your due date, your body produces prostaglandins and starts contracting. These things help the cervix efface (thin, soften, shorten, etc.) and prepare for delivery. Eventually, the cervix thins and shortens to the point that it’s as thin as a piece of paper.
Try thinking of your uterus as a turtleneck sweater. The cervix is the neck part. For most of your pregnancy, it stays in place to protect your baby. As contractions begin, they help stretch and shorten the neck. Your baby descends lower into the birth canal, too — and eventually, the neck of the sweater is so stretched and thin that it allows baby’s head to rest at the opening.
Effacement is different from dilation, which refers to how much the cervix has opened (from 1 centimeter to 10 centimeters). However, the two are closely related.
You may or may not have symptoms as your cervix effaces. Some people feel nothing at all. Others may experience irregular contractions that are uncomfortable but not necessarily as painful as labor contractions.
Other possible symptoms:
- loss of mucus plug
- increase in vaginal discharge
- feeling like your baby has dropped lower into your pelvis
Keep in mind that there are a lot of sensations you’ll experience at the end of your pregnancy. It may be difficult to pinpoint whether what you’re feeling is due to dilation, effacement, early labor, or just general aches and pains.
Related: Labor and delivery signs
Effacement is measured in percentages ranging from 0 to 100 percent. You’re considered 0 percent effaced if your cervix is longer than 2 centimeters, about the same size as the raised lip of a standard wine bottle.
When you’re 50 percent effaced, the cervix is around the size of the neck of a Mason jar. When you’re 100 percent effaced, your cervix has completely thinned out so it’s as thin as a sheet of paper.
Your OB-GYN or midwife will likely offer cervical checks as you get closer to your due date. During these checks, they can tell you how effaced and dilated you are.
Checking your cervix at home can be tricky, especially if you don’t know what you’re looking for. If you do choose to check your own cervix, make sure you wash your hands thoroughly. It may also be a good idea to clip your nails first.
- Slowly insert your index and middle fingers into the vagina — being careful not to spread bacteria from the anus.
- Reach to the end of the vaginal canal and feel for the texture and thickness of your cervix.
- If what you feel is very hard and thick, you’re likely not very effaced.
- If it feels mushy and thin, you may be making some progress.
Again, this can be very difficult to understand on your own without years of practice. Your healthcare provider has more training to determine exactly how effaced you might be. And don’t check your own cervix if your water has broken or if you have other complications, like infection, placenta previa, preterm labor, or a cerclage in place.
Cervical effacement generally begins in the later weeks of pregnancy. However, it can sometimes occur sooner, which is one reason OB-GYNs sometimes prescribe bed rest. You may even remember your healthcare provider measuring the length of your cervix from time to time via ultrasound — this is the very reason.
Both effacement and dilation are the result of your uterus contracting. While there’s no average time it takes to progress from 0 to 100 percent, you can’t fully dilate to 10 centimeters until you’re fully effaced. The two go hand in hand.
If you’re very close to or beyond your due date and would like to move things along, you may try having sex to ripen your cervix. Semen contains a high concentration of prostaglandins that may help it soften and thin out. But don’t have sex if your OB has instructed you not to for some reason or if your water has already broken.
Related: The 3 stages of labor explained
This probably isn’t the answer you want to hear, but you can be varying degrees of dilated or effaced for several days — or even weeks — before true labor begins. Alternatively, you might not be dilated or effaced at all and still go into labor within hours.
First-time moms tend to efface before they dilate. The opposite may be true if you’ve already had one or more babies.
Most of the effacement happens in the early stage of labor, when your cervix is dilating from 0 to 6 centimeters. This stage generally lasts 14 to 20 hours or more for a first-time mom, but (of course) all timelines are individual.
No matter how long it takes, you’ll not start trying to push your baby out into the world until you are 100 percent effaced and 10 centimeters dilated.
Effacement isn’t necessarily a reason to call your OB. That said, do get in touch if you experience bleeding, contractions that come every 5 minutes and last 45 to 60 seconds (and get stronger and closer together), or if your water breaks.
Otherwise, your cervix will eventually thin out and open enough to allow your baby’s head and body to pass through your vagina. All that progress and change are pretty amazing if you think about it. And what’s even more mind-blowing is that your body will eventually return to its pre-pregnancy state.
While it’s easy to get caught up in all the numbers and percentages, your job is to power through and deliver your baby into the world. Try to relax your body and mind and — most importantly — remember to breathe. You’ve got this, mama!