What Bishop score is favorable for induction?

A Bishop score ≥ 8 is considered favorable for induction, with a high likelihood of successful vaginal delivery similar to spontaneous labor. Scores ≤ 6 are considered unfavorable and may benefit from cervical ripening before induction. Scores of 6–8 are intermediate.

How is the Bishop score used clinically?

The Bishop score helps clinicians decide whether to proceed with induction or to first ripen the cervix using methods such as prostaglandins, mechanical dilators (Foley balloon), or misoprostol. A higher Bishop score is associated with shorter labor duration and higher vaginal delivery rates.

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Bishop Score Calculator

Assess cervical favorability to predict likelihood of successful labor induction.

Cervical Examination

Dilation (cm)

Effacement (%)

Fetal Station

Cervical Consistency

Cervical Position

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Select all parameters to calculate Bishop Score.

≤5Unfavorable cervix — cervical ripening recommended before induction

6–7Intermediate — consider cervical ripening

≥8Favorable cervix — high likelihood of successful induction

Disclaimer: For educational purposes only. Not a substitute for clinical judgment.

When to use

The Bishop Score is used before labor induction to assess cervical readiness. A higher score predicts greater likelihood of successful vaginal delivery with induction.

Clinical pearls

A Bishop Score ≥8 is associated with a likelihood of successful vaginal delivery similar to spontaneous labor.
An unfavorable cervix (Bishop ≤5) benefits from cervical ripening agents (prostaglandins, mechanical dilation).
The Bishop Score is subjective — interobserver variability exists, especially for effacement and consistency.

References

Bishop EH. Pelvic scoring for elective induction. Obstet Gynecol. 1964;24:266-268.
ACOG Practice Bulletin No. 107: Induction of Labor. Obstet Gynecol. 2009;114(2):386-397.

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About This Tool

What Is the Bishop Score?

The Bishop Score is a pre-labor scoring system developed by Dr. Edward Bishop in 1964 to assess the likelihood of successful induction of labor. It evaluates five components of the cervical examination: dilation, effacement, station, consistency, and position. Each component is assigned 0–3 points (consistency and position max at 2), yielding a total score from 0 to 13. The score helps obstetricians determine whether the cervix is favorable for induction and whether cervical ripening agents are indicated.

Clinical Application

A Bishop Score ≥8 generally indicates a favorable cervix with a high probability of successful vaginal delivery, comparable to spontaneous labor onset. Scores ≤5 indicate an unfavorable cervix, and cervical ripening is recommended before induction to reduce the risk of cesarean delivery and prolonged labor. Ripening methods include prostaglandin E₂ (dinoprostone), prostaglandin E₁ (misoprostol), and mechanical methods (Foley catheter balloon). The intermediate range (6–7) requires clinical judgment regarding the need for ripening.

Limitations and Modern Practice

The Bishop Score has significant interobserver variability, particularly for subjective parameters like consistency and effacement. Some institutions use a simplified score omitting consistency and position. Transvaginal ultrasound cervical length measurement has emerged as an alternative or complementary assessment, with cervical length <25 mm correlating with a favorable Bishop Score. Despite its age and limitations, the Bishop Score remains the most widely used clinical tool for pre-induction cervical assessment and is endorsed by ACOG and WHO guidelines.

🔑 Clinical Pearls

Nulliparous women generally require a higher Bishop Score for successful induction than multiparous women.
Misoprostol (PGE₁) is contraindicated in patients with prior cesarean delivery due to uterine rupture risk.
Mechanical ripening (Foley balloon) has a lower risk of tachysystole compared to prostaglandins.
The Bishop Score does not account for factors like BMI, gestational age, or indication for induction, which also influence success.

Key References

Bishop EH. Pelvic scoring for elective induction. Obstet Gynecol. 1964;24:266-268.
ACOG Practice Bulletin No. 107: Induction of Labor. Obstet Gynecol. 2009;114(2):386-397.
Kolkman DG, et al. The Bishop Score as a predictor of labor induction success. Am J Perinatol. 2013;30(8):625-630.

Formula last verified: February 2026