Bishop Score Calculator
Estimate your bishop score with our free gynecology & pregnancy calculator. See reference ranges, risk factors, and next-step guidance.
Formula
Bishop Score = Dilation (0-3) + Effacement (0-3) + Station (0-3) + Consistency (0-2) + Position (0-2)
Each cervical characteristic is scored independently. Dilation measures cervical opening (0-5+cm), effacement measures cervical thinning (0-80+%), station measures fetal descent (-3 to +2), consistency evaluates firmness (firm to soft), and position notes cervical direction (posterior to anterior). Total range is 0-13.
Worked Examples
Example 1: Favorable Cervix Assessment
Problem: A 39-week pregnant woman presents with dilation 3cm (score 2), effacement 70% (score 2), station -1 (score 2), soft consistency (score 2), and anterior position (score 2). What is her Bishop Score?
Solution: Dilation: 3cm = 2 points\nEffacement: 70% = 2 points\nStation: -1 = 2 points\nConsistency: soft = 2 points\nPosition: anterior = 2 points\nTotal Bishop Score = 2 + 2 + 2 + 2 + 2 = 10
Result: Bishop Score: 10/13 (Favorable) - High likelihood of successful induction, oxytocin induction appropriate
Example 2: Unfavorable Cervix Assessment
Problem: A 41-week pregnant woman presents with dilation closed (score 0), effacement 20% (score 0), station -3 (score 0), firm consistency (score 0), and posterior position (score 0). What is her Bishop Score?
Solution: Dilation: closed = 0 points\nEffacement: 20% = 0 points\nStation: -3 = 0 points\nConsistency: firm = 0 points\nPosition: posterior = 0 points\nTotal Bishop Score = 0 + 0 + 0 + 0 + 0 = 0
Result: Bishop Score: 0/13 (Unfavorable) - Cervical ripening recommended before induction attempt
Frequently Asked Questions
What is the Bishop Score and why is it used in obstetrics?
The Bishop Score is a standardized clinical assessment tool developed by Dr. Edward Bishop in 1964 to evaluate cervical readiness for labor induction. It assigns numerical values to five cervical characteristics: dilation, effacement, station, consistency, and position. The total score ranges from 0 to 13, with higher scores indicating greater likelihood of successful induction. Healthcare providers use this scoring system to determine whether a patient needs cervical ripening before induction or if the cervix is already favorable enough for direct oxytocin administration. The Bishop Score remains one of the most widely used pre-induction assessment tools in modern obstetric practice worldwide.
What Bishop Score is considered favorable for labor induction?
A Bishop Score of 8 or higher is generally considered favorable for labor induction, meaning the cervix is ready and induction is likely to succeed. Scores between 5 and 7 are considered moderately favorable, where induction can proceed but may require longer time or additional interventions. Scores of 4 or below indicate an unfavorable cervix that would benefit from cervical ripening agents before attempting induction. Research shows that patients with a Bishop Score above 8 have induction success rates comparable to spontaneous labor outcomes. The threshold may vary slightly between institutions, with some using 6 as their cutoff for favorable status.
How is cervical dilation scored in the Bishop Score system?
Cervical dilation is scored on a scale of 0 to 3 points in the Bishop Score system. A closed cervix receives 0 points, dilation of 1-2 centimeters receives 1 point, dilation of 3-4 centimeters receives 2 points, and dilation of 5 centimeters or more receives the maximum 3 points. Dilation refers to how wide the cervical opening has become, measured during a digital vaginal examination. This component is one of the most predictive individual elements of the Bishop Score because significant dilation indicates the cervix has already begun the process of preparing for delivery. Progressive dilation over time is also an important clinical indicator of labor progress.
What does cervical effacement mean and how does it affect the score?
Cervical effacement refers to the thinning and shortening of the cervix, measured as a percentage from 0% (full length, about 3-4cm) to 100% (paper thin). In the Bishop Score, effacement of 0-30% scores 0 points, 40-50% scores 1 point, 60-70% scores 2 points, and 80% or more scores 3 points. Effacement is crucial because it indicates how much the cervix has softened and prepared for dilation. A fully effaced cervix is much more likely to dilate rapidly during induction compared to a thick, uneffaced cervix. Many clinicians consider effacement to be equally important as dilation when assessing cervical readiness for labor.
What is fetal station and how is it measured for the Bishop Score?
Fetal station describes the position of the presenting part of the baby (usually the head) relative to the ischial spines of the maternal pelvis. Station is measured from -3 (floating above the pelvis) to +3 (crowning at the vaginal opening), with 0 being at the level of the ischial spines. In the Bishop Score, a station of -3 receives 0 points, -2 receives 1 point, -1 or 0 receives 2 points, and +1 or +2 receives 3 points. A lower station (baby further descended into the pelvis) contributes to a higher Bishop Score and suggests that labor induction is more likely to succeed because the baby is already engaged.
How do cervical consistency and position contribute to the Bishop Score?
Cervical consistency and position each contribute up to 2 points to the Bishop Score. Consistency evaluates how soft the cervix feels: firm (like the tip of your nose) scores 0, medium scores 1, and soft (like the inside of your cheek) scores 2 points. A softer cervix is more favorable for induction because it dilates more easily. Cervical position refers to the direction the cervix faces in the vagina: posterior (facing backward) scores 0, mid-position scores 1, and anterior (facing forward) scores 2 points. An anterior cervix is easier to access and typically indicates the cervix is preparing for labor naturally.