A Bishop score is a number between 0 and 13 that tells your healthcare provider how ready your cervix is for labor. It’s checked before an induction to predict whether inducing labor is likely to lead to a vaginal delivery. A score of 8 or higher means your body is primed and induction will probably go smoothly. A score of 5 or lower means your cervix isn’t ready yet and may need help softening and opening before labor can begin.
The Five Things Being Measured
The Bishop score was developed in 1964 by Dr. Edward Bishop and is still the most widely used method for evaluating cervical readiness. During a cervical exam, your provider checks five specific things and assigns points for each one:
- Dilation: How open your cervix is, measured in centimeters. A closed cervix scores 0; one that’s already 5 or more centimeters open scores 3.
- Effacement: How thin your cervix has become. Before labor, the cervix is thick and long. As it thins out (expressed as a percentage), it scores higher. Zero percent means no thinning at all; 80% or more scores 3.
- Station: How far down your baby’s head has descended into your pelvis. The midpoint of the pelvis is called “0 station.” A baby sitting high at negative 3 scores 0, while one that’s moved well past the midpoint scores 3.
- Position: Whether your cervix is tilted toward the back (posterior), in the middle, or moved forward (anterior). An anterior cervix is more favorable and scores higher.
- Consistency: How soft your cervix feels. Providers often compare a firm cervix to the tip of your nose and a soft one to the inside of your lip. Softer scores higher.
Dilation, effacement, and station are each scored from 0 to 3 points. Position and consistency are scored from 0 to 2 points. All five are added together for your total.
What Your Score Means
The total ranges from 0 to 13, and providers generally interpret it in three tiers. A score of 8 or higher is considered favorable, meaning your cervix is already soft, thinning, and partially open. Labor is likely to start on its own soon, and if induction is needed, a vaginal delivery is very likely.
A score of 6 to 7 falls in a gray zone. Induction may or may not go smoothly, and your provider will weigh other factors like your medical history and the reason for induction before deciding how to proceed.
A score of 5 or lower means your cervix hasn’t started preparing for labor yet. This is called an “unfavorable” cervix. It doesn’t mean you can’t be induced, but it does mean the process will likely take longer and may require extra steps to soften and open the cervix first.
How the Score Predicts Induction Success
Research consistently shows that the Bishop score is one of the strongest predictors of whether induction will end in a vaginal delivery. In a large study of 696 women, those with a score of 5 or higher had a 75% success rate for vaginal delivery, compared to 56% for those scoring below 5. A modified version of the scoring system found that women scoring 5 or above delivered vaginally 91% of the time, versus 67% for those below that threshold.
A low score also correlates with a higher chance of cesarean delivery. In first-time mothers, a Bishop score of 5 or less more than doubled the odds of ending up with a cesarean section compared to women with higher scores. That said, a low score is not a guarantee of surgical delivery. It simply means the induction process may be longer and more involved.
What Happens With a Low Score
When your Bishop score is low, your provider will typically recommend cervical ripening before starting the medications that trigger contractions. The goal is to soften, thin, and slightly open your cervix so it responds better when labor is induced. Two main approaches are used, sometimes together.
Mechanical ripening involves placing a small balloon catheter through the cervix. The balloon applies gentle, steady pressure that encourages the cervix to dilate. Pharmacologic ripening uses medications (placed vaginally or taken by mouth) that mimic the natural hormones your body produces to prepare the cervix. Current guidelines from the American College of Obstetricians and Gynecologists suggest that combining both methods can shorten the time from hospital admission to delivery.
For women with very low scores (0 to 3), the choice of ripening method matters more. One study found that pharmacologic ripening in this group cut the cesarean rate roughly in half compared to jumping straight to contraction-stimulating medication (33% versus 59%). Once the Bishop score reaches the mid-range (4 to 6), the specific ripening method matters less, and outcomes are similar regardless of approach.
How the Exam Feels
The Bishop score is assessed during a standard cervical exam. Your provider inserts two gloved fingers into the vagina to feel the cervix and estimate its dilation, thickness, softness, and position, while also checking how far down the baby’s head has dropped. The whole assessment takes under a minute. It can feel uncomfortable, similar to a Pap smear with more pressure, but it’s brief. The score is typically checked at one of your later prenatal appointments or when you arrive at the hospital for induction.
Limitations of the Score
The Bishop score is subjective. Two providers examining the same cervix might assign slightly different numbers, especially for effacement and consistency. Ultrasound measurements of cervical length and angle have shown higher accuracy in some studies. One study found that cervical length measured by ultrasound had 97% sensitivity and 97% specificity for predicting vaginal delivery, compared to 89% sensitivity and 88% specificity for the Bishop score alone. Despite this, the Bishop score remains the standard in most labor and delivery units because it’s quick, requires no equipment, and gives providers a shared language for describing cervical readiness.
Your Bishop score can also change. A cervix that scores a 3 one week might score a 6 the next as your body naturally prepares for labor. If your induction isn’t urgent, your provider may recommend waiting and rechecking, since even a few more points can meaningfully improve the odds of a straightforward delivery.