Cervix Effaced During Pregnancy | Softening before birth

As you near the end of your pregnancy, your midwife might start to talk about effacement. Cervical effacement is one of the things your body needs to do to make sure your baby can pass smoothly through the birth canal, or vaginal canal. “Effaced during pregnancy” is a term that can be confusing for expectant mothers.

Cervical effacement and cervical dilation are two processes your cervix must go through before a vaginal birth.

What is cervical effacement?

The cervix sits at the bottom of your uterus; it is known as the ‘neck of the womb’ and sits between the uterus and the vagina. During pregnancy, your cervix remains closed. If you have a vaginal birth, your cervix will need to open during active labor for your baby to be born. Before birth, the cervix begins to soften and thin out, and this process is known as cervical effacement. Cervical effacement can occur before active labor as your body prepares for the birth of your baby.

What does cervix effaced during pregnancy mean?

When not effaced, the cervix is around 1.2-2 inches long and feels firm, like the tip of your nose. When effacement begins, the cervix softens and feels more like a dimple. Effacement is measured in percentages; once your cervix is 100 percent effaced, you are fully effaced.

The position of the cervix changes during the effacement process. During pregnancy, your cervix is usually posterior, which means it points towards your back and is difficult to reach. Some women find their cervix remains in the mid position during pregnancy, making it easier to reach. During effacement, however, as well as thinning and softening, your cervix will move forward to an anterior position, ready for birth.

When does effacement during pregnancy start and how long does it take?

There is no hard and fast rule for when changes to the cervix happen; the process varies from woman to woman. One study published in the American Journal of Perinatology found a wide range of normal time lengths for cervical effacement. It might take hours or days. It could happen just before labor starts, or weeks before, as your body prepares for the big day. Unfortunately, being effaced does not guarantee that you’ll go into labor soon.

Often, first-time mothers will experience effacement before dilation. In subsequent pregnancies, it is more common for some dilation to occur before the cervix is fully effaced. Your healthcare provider might check for signs of cervical effacement and dilation when you are in labor, if you consent to examinations.

Effacement and dilation might occur during early labor when your body is gearing up for labor. Once your cervix is 4 cm dilated, you are considered to be in active labor.

Signs of cervical effacement

The following signs or ‘cervical effacement symptoms’ might be clues that your cervix is starting to efface:

• Irregular contractions (Braxton Hicks contractions)
• Losing your mucus plug
• Increased vaginal discharge
• Feeling the baby drop down lower into your pelvis.

Unfortunately, the above symptoms do not guarantee your baby will be born soon, but you can relax in the knowledge that your body has started its preparations.

What is the difference between cervical effacement and dilation?

During effacement, the cervix shortens and becomes thinner and softer but will still cover the entrance to the uterus. Once cervical dilation starts, your cervix will begin to open to create space for your baby to pass through.

Can you be effaced but not dilated?

Yes, your cervix can be fully effaced before dilation begins. Alternatively, your cervix can start dilating before you’re fully effaced. Everybody is different; some people efface and dilate simultaneously.

How is effacement measured?

If you wish, your doctor or midwife will perform a vaginal examination to measure your cervical effacement. Your care provider will use a sterile glove and insert two fingers into your vagina to reach your cervix to assess it. Remember, this examination is optional; if you don’t want it, you’re under no pressure to consent.

The cervix hangs down into the vagina. Before effacement begins, there are usually 1-2 inches of cervical rim extending downward. As effacement occurs, the cervix is drawn up into the lower part of the uterus and there is less cervical rim. Eventually, it will seem to disappear into the uterus.

Measurements of effacement are referred to in percentages. If there is no change, your care provider will note 0 percent effacement. If your cervix is half its ordinary thickness, this is indicated as 50 percent effacement. When you are 100 percent effaced, your cervix has completely thinned.

What causes effacement during pregnancy?

Toward the end of pregnancy, your body produces a hormone called prostaglandin. This hormone acts on the cervix to soften it, allowing it to stretch and dilate.

You might be familiar with the sensation of Braxton Hicks contractions. Most pregnant women experience Braxton Hicks contractions in the second or third trimester. In the final weeks of pregnancy, Braxton Hicks contractions might become stronger and more intense, helping to move the baby into a good position, as well as engaging the head into the pelvis. This encourages pressure on the cervix and promotes more effacement.

Although engagement isn’t necessary before labor begins, it’s common for the baby’s head to drop into the pelvic brim to some degree during the last weeks of pregnancy.

What happens after effacement?

As your cervix thins completely, at some point, uterine contractions will begin. These contractions will be different from Braxton Hicks, as they will begin to dilate (open) the cervix for your baby to make an entrance into the world.

Early labor contractions might be irregular and mild but, over time, they will strengthen and become more regular. Early stages of labor can take some time – until the cervix is dilated to around 6 cm. At this stage, contractions can intensify and get closer together and cervical dilation can happen more rapidly. Once the cervix dilates completely (10 cm), expulsive contractions will push the baby down into the birth canal to be born.

What if I am not effaced?

In a perfect world, we would not be concerned about whether or not a cervix is effacing. When you’re feeling utterly fed up, heavily pregnant and dealing with sleepless nights and backache, you can be excused for wondering when labor will start. Effacement doesn’t mean labor will happen soon, though, and it can be disheartening to hear your cervix is 0 percent effaced; sometimes it’s better not to know.

In some situations, it might be necessary to have your baby earlier. If you wish to avoid an induction, you might prefer to try preparing your cervix with one of these methods:

• Sex. Sperm has prostaglandins, which can encourage the cervix to begin to thin. This method is safe unless your waters have broken or you’ve started to lose your mucus plug, as this increases the risk of infection
• Optimal fetal positioning. Keeping your body in balance and in a good position encourages the baby to move into a head-down, tucked-chin position. Sitting upright and walking can also encourage the baby into a good position, allow engagement and encouraging effacement.

Some women use evening primrose oil; however, this is not recommended. Although it was traditionally believed to prepare the cervix for labor, the NIH states: ‘Evening primrose oil may be safe for use during pregnancy and while breastfeeding, but the evidence is not conclusive’.

Cervical effacement is a crucial part of labor and can take some time. Many care providers perform internal cervix checks during the last weeks of pregnancy to determine how likely it is you will go into labor. These routine checks are not necessary and increase the risk of infection exposure. You can say no.

What your cervix is doing at a particular moment doesn’t predict what your cervix will be doing in the next few hours, days or weeks. If your cervix is thinning, it can safely do so without needing to be checked.

Although it is much easier said than done, try not to spend your final days or weeks of pregnancy fretting about when labor will start.

Instead, focus on preparing for your baby and relaxing. Slow down, take it easy, and do the things that make you feel contented. Trust that your body is busy with preparations and will let you know when it’s time.

Recommended reading: When Should A Baby Engage In Pregnancy?