What Does Your Bishop Score Mean?

Toward the end of pregnancy, your doctor may use something called the Bishop score to determine your chances of having a successful vaginal birth in the near future. 

Your provider is probably keeping tabs on what your score is when you go for prenatal appointments in the last month of pregnancy, even if you've never heard of it before. Don't worry—even if they are not be sharing it with you (because you’re too pregnant to be crunching numbers!), we can help explain how a Bishop score is calculated and how it informs them about the progress of your pregnancy.

What Is the Bishop Score?

The Bishop score is basically a readiness rating for your cervix. In order to vaginally deliver a baby, your cervix needs to be soft, thin, open, and in the right position to allow the baby to move through the birth canal. 

A simple vaginal exam during the late stages of pregnancy can tell your provider most of what they need to know about how ready—or not!—your cervix is for labor. All together, the different elements of this assessment add up to something called your Bishop score (named for Edward Bishop, the physician who invented the scale back in the 1960s). 

What Does It Mean?

Healthcare professionals use the Bishop score to determine a two things about an expectant mother’s prospects for birth:

• Whether or not they are likely to go into labor naturally on their own and when, and
• Whether or not an induced labor is likely to result in a successful vaginal birth (i.e. not one that requires a c-section).

This is important information for your provider to work out. Why? Here are a few scenarios where determining your Bishop score is useful.

• You are past your due date, but showing signs of cervical readiness. If so, your provider may allow you to continue waiting for labor to start spontaneously.
• You are past your due date but not showing signs of cervical readiness, or maybe have a medical condition (like gestational diabetes) that increases your risk for delivery complications. In this case, your provider may choose to induce labor since it’s not likely you’ll go into labor on your own or it may not be wise to wait any longer.
• You know you will need an induction, but your provider wants more information on whether that induction is likely to result in a successful vaginal delivery or not.

As you can see, there are many outcomes and possible avenues for decision-making once your Bishop score has been calculated. Knowing your score gives your doctor some important clues about how to proceed with your pregnancy if you have any complications or are more than 40 weeks pregnant.

How Is It Calculated?

There are five metrics taken into consideration when working out your Bishop score. Usually, a physical exam from your provider is all that’s needed to measure these five factors, but sometimes an ultrasound is required to get a better look at the position of your baby. 

1. Cervical dilation. This refers to how many centimeters your cervix has opened. During a vaginal delivery, you will need to be close to 10 centimeters dilated before you can start pushing. 
2. Cervical effacement. This is how thick or thin your cervix is and it’s measured in percentages. A measurement of 0 % effacement means your cervix is as thick, or long, as it normally is. At 100% effacement, your cervix is paper thin and ready for labor. 
3. Cervical position. If your cervix is low, it has moved further down into the pelvis to make way for the baby’s head. This means your body is getting ready for labor. 
4. Cervical consistency. Does your cervix feel hard and firm or soft and pliable? A soft rating means your cervix is preparing to stretch itself and accommodate your baby’s delivery. 
5. Fetal station. This refers to the position of your baby’s head relative to your pelvis and spine. Fetal station moves along a grade of positive and negative numbers, with negative numbers meaning the baby’s head is further up the birth canal—and father away from labor—and positive numbers meaning your baby’s head is moving down the canal into a birthing position.

A score below 5 means you probably won’t be going into labor soon, and the odds are not very good that you could have a successful vaginal delivery if you were induced (in other words, your doctor may decide to perform a c-section). 

A score of 6 or 7 is tricky; it doesn’t reveal much either way about your likelihood of having a spontaneous birth or successful induction. If you score a 6 or 7 on the Bishop scale, your doctor would most likely consider your overall medical history and may consider things like:

• How far along or past your due date are you?
• Do you have any existing conditions, like preeclampsia, which warrant labor interventions?
• Is this your first pregnancy, or do you have a history of needing to be induced in prior deliveries?

Of course, if you have questions, don’t be afraid to ask your doctor. They have probably treated other patients in similar positions as yours, and will have the experience needed to weigh pros and cons of inducing in hopes of a vaginal delivery, taking a wait-and-see approach, or scheduling a c-section.