Bishop Score Calculator

What is the Bishop Score?

The Bishop Score is a standardized scoring system developed by Dr. Edward Bishop in 1964 to assess cervical readiness for labor induction. It evaluates five components of the cervical examination to predict the likelihood of successful vaginal delivery following induction.

A higher Bishop Score indicates a more favorable (or "ripe") cervix, which correlates with a higher chance of successful induction.

The five components

1. Dilation (0-3 points)

Cervical dilation measures how open the cervix is:

Finding	Score
Closed	0
1-2 cm	1
3-4 cm	2
5+ cm	3

2. Effacement (0-3 points)

Effacement measures how thin the cervix has become:

Finding	Score
0-30%	0
40-50%	1
60-70%	2
80%+	3

3. Station (0-3 points)

Station measures the position of the fetal head relative to the ischial spines:

Finding	Score
-3	0
-2	1
-1 or 0	2
+1 or +2	3

4. Cervical consistency (0-2 points)

How firm or soft the cervix feels:

Finding	Score
Firm	0
Medium	1
Soft	2

5. Cervical position (0-2 points)

The position of the cervix in the vagina:

Finding	Score
Posterior	0
Mid-position	1
Anterior	2

Score interpretation

Total score range: 0-13

Score	Interpretation	Likelihood of Vaginal Delivery
0-5	Unfavorable	Low without cervical ripening
6-7	Moderate	Moderate (ripening may help)
8-13	Favorable	High

Key thresholds

• Score ≥8: Cervix is favorable for induction
• Score <6: Cervical ripening is typically recommended
• Score 6-7: Clinical judgment based on parity and other factors

Parity considerations

Nulliparous (first baby)

• Typically require Bishop Score ≥8 for favorable induction
• More likely to benefit from cervical ripening
• May have longer labor duration

Multiparous (previous births)

• May succeed with Bishop Score ≥6
• Cervix often responds more quickly to induction
• Previous vaginal delivery is a positive predictor

Simplified Bishop Score

A simplified version uses only three components:

• Dilation
• Effacement
• Station

Simplified Score ≥5 may be as predictive as the full Bishop Score ≥8 for successful induction.

Clinical applications

When to calculate

The Bishop Score is typically assessed:

• Before planned labor induction
• When considering expectant management vs. induction
• To guide the choice of induction method
• To counsel patients about expected outcomes

Induction methods by score

Bishop Score	Recommended Approach
<4	Cervical ripening (prostaglandins, mechanical)
4-6	Ripening or low-dose oxytocin
>6	Oxytocin or amniotomy

Cervical ripening methods

Pharmacological

Prostaglandin E2 (Dinoprostone)

• Cervidil (controlled-release insert)
• Prepidil (gel)

Prostaglandin E1 (Misoprostol)

• Oral or vaginal administration
• More cost-effective

Mechanical

Foley catheter

• Inserted through cervix
• Balloon inflated to apply pressure
• Lower risk of hyperstimulation

Membrane sweeping

• Outpatient option
• May reduce need for formal induction

Factors affecting success

Positive predictors

Factor	Impact
High Bishop Score	Strong predictor
Multiparous	Better outcomes
Previous vaginal delivery	Significant predictor
Spontaneous labor onset	Good sign
Favorable maternal age	Generally better outcomes

Challenges

Factor	Impact
Low Bishop Score	May require ripening
Nulliparous	Longer labor, more interventions
Maternal obesity	May affect exam and labor
Large baby	Potential for dystocia

Limitations

What the Bishop Score cannot do

• Not a diagnostic test: Does not guarantee outcomes
• Subjective components: Examiner variability exists
• Single point in time: Cervix can change rapidly
• Doesn't capture all factors: Fetal position, maternal pelvis not assessed

Modern alternatives

Some institutions supplement or replace Bishop Score with:

• Transvaginal ultrasound cervical length
• Fetal fibronectin testing
• Combined scoring systems

Evidence and updates

Historical perspective

The Bishop Score was developed in 1964 when:

• Induction methods were limited
• C-section rates were lower
• Monitoring was less sophisticated

Current evidence

Recent studies suggest:

• Simplified scores may work as well as full score
• Cervical length adds predictive value
• Success depends on many factors beyond Bishop Score

Example assessment

Case: Term pregnancy, planned induction

Cervical exam findings:

• Dilation: 1 cm (Score: 1)
• Effacement: 50% (Score: 1)
• Station: -2 (Score: 1)
• Consistency: Medium (Score: 1)
• Position: Mid (Score: 1)

Total Bishop Score: 5

Interpretation:

• Unfavorable cervix
• Cervical ripening recommended before oxytocin
• Consider Foley catheter or prostaglandins

Patient counseling

What to tell patients

With a favorable score (≥8):

• "Your cervix is ready for induction"
• "You have a good chance of vaginal delivery"
• "We can proceed with oxytocin or breaking your water"

With an unfavorable score (<6):

• "Your cervix isn't quite ready yet"
• "We'll use medication or a catheter to help ripen it"
• "This may take several hours or overnight"

Summary

The Bishop Score:

1. Assesses five components: dilation, effacement, station, consistency, position
2. Range is 0-13: Higher scores are more favorable
3. Score ≥8 typically indicates favorable cervix for induction
4. Score <6 suggests cervical ripening may be beneficial
5. Parity matters: Multiparous patients may succeed with lower scores
6. One factor among many: Clinical judgment remains essential

The Bishop Score remains a useful clinical tool but should be integrated with other clinical factors when making induction decisions.