What You Need to Know About Your Cervix
Starting around your 36th week of pregnancy, your provider may begin offering to perform cervical checks at each of your final appointments to asses your cervical progress.
Now, when I say that, you’re probably automatically thinking of numbers between 1-10 cm, am I right?
But cervical dilation is not the only way your cervix changes as your body prepares to bring your baby into the world.
SO, WHAT DOES THE CERVIX DO?
While dilation is the most oft discussed aspect of cervical progress, it is only one of four ways the cervix changes leading up to and during labor. In addition to opening, the cervix must also efface, soften, and move forward.
Here’s a quick explanation of each of these changes:
Effacement, noted as a percentage, is the thinning of the cervical walls. You may hear that you are “100% effaced” of “fully effaced,” which means the cervical walls have reached the maximum expected thinness.
Cervical consistency refers to how soft or how firm your cervix is. As labor progresses, your cervix will soften from about the firmness of the tip of your nose to about the consistency of your earlobe between your fingers.
Cervical positioning shifts during labor, too, so that your cervix moves from a posterior (or back-facing) position to an anterior (or belly-facing) position.
And, of course, dilation is the opening of the cervix, which is considered “complete” once the cervix is dilated to 10 centimeters.
AND WHEN DOES THE CERVIX DO THIS?
While some of these changes may begin before labor is really happening (this is why your provider may mention that you are already 3cm dilated or 20% effaced even at your prenatal appointments), most of them happen—wait for it—during labor.
Much of the progress the cervix makes depends on long, strong, and frequent contractions that move baby deeper into the pelvis and force baby to press their head against the cervix. This consistent pressure helps the cervical walls to thin (effacement) and the cervix to open (dilate).
YOUR BISHOP SCORE
You may be wondering, “Where does all of this knowledge comes into play for me?”
Your Bishop Score.
The Bishop Score is a “score” given to the cervix during a vaginal exam prior to labor; it’s based on an assessment of the four previously mentioned cervical categories, plus fetal station, or how low baby’s head is in the pelvis.
HOW IT WORKS
During the exam, each category is assigned points, and at the end these points are totaled to give you The Bishop Score. The highest you can score is 13 points, and where you fall on the scale serves as a potential indicator for the likelihood that labor will start on its own and/or that an induction will be successful.
A Bishop Score of 5 or less suggests that labor will not likely start any time soon without being induced, and a low score also often indicates that even an induction would probably be unsuccessful if attempted.
However, a Bishop score of 9+ suggests that labor will likely begin on its own, and it is only a score of 8 or more that is considered reliably predictive that an induction will be successful.
Knowing what actually happens and what all of the numbers mean can be really helpful for adjusting your perspective as you wait for the big day to arrive. Also, it can really help you to better understand your provider’s recommendations and engage them in important conversations about your specific circumstances.