Bishop Score

The Bishop score is a way for your pregnancy care provider to see how ready your body is for labor. It checks for changes in your cervix (the opening to the uterus) and how low your baby’s head is in your pelvis. The final score helps providers estimate if inducing labor will lead to a successful vaginal delivery.

Your score can range from 0 (zero) to 13. A lower score means your cervix isn’t ready for an induction. A higher score means there's a better chance of a successful induction.

Your provider typically calculates your Bishop score once you’re 40 weeks pregnant, since they usually don’t consider inducing you until you reach your due date. Your provider may use it earlier if there’s a medical reason to consider induction.

The score has some limitations, though. It only estimates. This means it can’t say for sure that induction will lead to a successful vaginal delivery. For example, you can have a low score and still go into labor naturally. It also doesn’t account for factors like health conditions or if you’ll develop strong contractions. The score can also vary slightly between providers because some parts of the exam are subjective — they're based on how something feels.

The Bishop score is named after Edward Bishop. He created the score in 1964 to help predict the success of inducing labor using five criteria. It’s sometimes called a cervix score or a pelvic score.

How is the Bishop score calculated?

Your healthcare provider uses these five factors to calculate your Bishop score:

• How open your cervix is (dilation): Your provider checks how open your cervix is. The opening is measured in centimeters. During labor, the cervix opens to about 10 centimeters.
• How thin your cervix is (effacement): As your body gets ready for labor, the cervix becomes thinner and shorter. Fully effaced (or 100% effaced) means your cervix is “paper-thin.”
• How soft your cervix feels (consistency): Your cervix becomes softer as labor gets closer. A soft cervix is usually a sign that your body is preparing for labor.
• Position of the cervix: The position of your cervix moves closer to your birth canal as labor nears. Providers refer to this as being anterior. If your position is posterior, you’re further away from labor.
• Fetal position (or fetal station): This measures the position of your baby’s head in relation to the ischial spine (a place in your pelvis). Healthcare providers give a rating based on if the head is above or below that point in your pelvis. A positive number means your baby’s head has descended into the birth canal. A negative number means your baby’s head is still high.

Each factor is given a score. Then, the five individual scores are added to get your final Bishop score. A higher Bishop score means inducing labor is likely to be successful.

How does my doctor measure my score?

Your pregnancy care provider calculates your Bishop score after a physical exam of your cervix. They’ll ask you to lay back on an exam table with your feet in stirrups. Then, they’ll insert a gloved finger into your vagina to feel your cervix. You may have some discomfort during a cervix exam, but it shouldn’t be painful.

They'll also check your baby’s position, either with an ultrasound or by feeling your abdomen. Your provider will then look at each part and give it a score based on the exam.

Your provider may not use the Bishop score if you have certain health conditions or if it's unsafe.

Bishop score chart

Each factor in the Bishop score has three or four options that reflect how favorable your cervix is. A favorable cervix means it's ready for labor.

The following chart is a Bishop score example:

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Bishop score calculator

For example, your Bishop score would be 7 if you:

• Are 4 centimeters dilated (2 points)
• Have an anterior cervical position (2 points)
• Have a cervix that's 50% effaced (1 point)
• Have a firm cervix (0 points)
• Have a fetal position of zero (2 points)

What does my Bishop score mean?

Your points for each of the five factors are added to give you a final score. The score ranges mean:

• Eight or more points: Your labor is likely to begin soon. If you were to be induced, successful vaginal delivery is likely.
• Six to seven points: Induction may or may not be successful. It’s a point where your healthcare provider would need to make a judgment call.
• Five and fewer points: Your body isn’t prepared for labor, and labor is unlikely to start naturally.

It’s important to know that your Bishop score is just one indicator of how likely you are to need an induction. It’s meant to help you and your healthcare provider make the best decision about your labor and delivery plans. Some people have low Bishop scores and have successful vaginal births after inductions. Some people with high Bishop scores have unsuccessful inductions.

What is a favorable score?

A favorable Bishop score means that you scored eight or higher. It means an induction has a better chance of success.

When does a Bishop score mean induction is necessary?

Inducing labor is based on several factors. Induction is typically necessary when certain medical conditions are present or when your healthcare provider feels it’s unsafe to wait for labor to progress naturally. The Bishop score is a tool healthcare providers use to help them make decisions, but it isn’t the only tool.