My Cervix is Gonna WHAT?

My Cervix is Gonna WHAT?

You're sitting in a hospital class or scrolling a mom group and suddenly you see it: that picture of a frosted donut or a raisin bagel, captioned: “YOUR CERVIX, DILATED 10 CM.”

Uhh...excuse me, my what is gonna what?
 

It may be hard to believe, but your cervical opening can truly widen approximately that much to allow your baby to pass through. It sounds horrifying, but once you learn about how marvelously your body works together with your muscles, your hormones, and your baby to facilitate birth, you'll understand how a little human can actually fit quite well through what appears to be such a small opening. Let's go over the cervix and the stages it goes through before and during birth.

What is the Cervix?

The cervix is the opening of your uterus – a thick neck of muscle in between your baby and your vagina. Your doctor feels your cervix by inserting two fingers deeply into your vagina. You can even wash your hands and feel it yourself if you're curious. The cervix is usually firm, tilted back, and closed up, keeping your baby inside your uterus. During labor, it moves forward, thins out, gets soft and squishy, and eventually opens to let the baby pass through. Click here to see an illustration of the cervix.

What is Cervical Ripening?

As your body begins to prepare for delivery, hormonal changes are activated which cause the cervix to soften, or “ripen”. It should normally be firm to the touch, but before or during labor your hormones will cause it to feel soft – like your lips. This is what is going on when your doctor examines your cervix and says whether or not it's “softened”.

What is Cervical Effacement?

Cervical effacement refers to the thickness of the cervix. When firm and closed, the cervix is usually about 2-3 centimeters thick. Before and during labor, hormones cause the cervix to become thinned out. It usually thins out before dilating more than a centimeter or so. Your doctor measures how thin, or how “effaced” your cervix is, in percentages. So at 0% effacement your cervix is unchanged – 2-3 centimeters thick. At 100% effaced, it is completely paper-thin and at this point you are usually in advanced labor. Click here to see an illustration of cervical effacement.

What is Cervical Dilation?

This is the part that seems a little nerve-racking to some parents. Is there really going to be a donut-sized opening inside me? The cervix dilates, or opens, little-by-little in pregnancy and labor. Your body produces hormones, your uterus contracts, and your baby wiggles downward - these components all work together to transform your cervix. At 1-2 centimeters, you can only fit one fingertip inside. At 10 centimeters, if the baby is moved down low enough you may be ready to start pushing! This is what's going on when your doctor or midwife examines your cervix and calls out the number.

When Does All This Happen?

Your cervix can go through all these changes before labor even begins, or they can all happen during labor. Every labor, every body, and every baby are different. You can walk around for two weeks at 5 centimeters dilated and 80% effaced, and then go into labor. You can go into labor at 0 centimeters and 0% effacement and have a baby within hours. Everyone is different!
 

That being said, here's a general rule of thumb for when to expect these changes to happen:

36+ weeks: cervix begins to move forward to an anterior position and can easily be felt during an exam

38+ weeks: cervix may be dilated 1-2 centimeters and slightly effaced

Early labor (light contractions every 7-10 minutes): 1-4 centimeters dilated, 50% effaced

Active labor (strong contractions every 3-5 minutes): 4-6 centimeters dilated, 50-100% effaced

Transitional labor (long, strong contractions close together): 7-10 centimeters dilated, 80-100% effaced

Checking the cervix prior to labor doesn't provide any indicators of when labor will start, or how long it will last – it only describes the current state of the cervix. Your doctor uses this information to help determine how successful a labor induction might be! The more soft, dilated, and effaced your cervix is prior to labor, the easier it will be for medications to induce contractions for a vaginal delivery.
 

Want to learn some more? Click here to read about the Bishop Score (how your doctor determines favorability for induction). Click here to read about how the cervix is medically softened for an induction.

To learn everything you need to know about birth and how your body and baby work together to make it happen, you should take a thorough, evidence-based, and fun childbirth class during pregnancy!