Bishop Score Calculator

Bishop Score Calculator for Obstetrics & Gynecology. NICE NG207 distinguishes scores of 6 or less from scores above 6 for induction-method decisions; its definition describes 8 or more as generally indicating cervical readiness. This tool therefore does not label 6 as favorable or collapse 7 into the highest-readiness group. None of these thresholds independently establishes a treatment, an induction start time or a safe route of birth.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

This is the original five-component, effacement-based Bishop calculation, with a maximum of 13 points. It adds the selected dilation, effacement, station, consistency and position contributions without assuming any unanswered item is zero. The numerical criteria are independently implemented; no publisher table or examination form is reproduced. The historical categories describe examination bands, not a continuous numerical equation. For example, 35% effacement is not silently rounded into a neighboring band. A clinician must reconcile such a finding with the scoring convention before selecting a category. Cervical length belongs to a different modification and cannot replace effacement here.

When to use this calculator

Use this calculation to document cervical readiness during an obstetric assessment when induction is being discussed. Record the examination time and use findings from one assessment. The clinical indication for induction must already be assessed separately. Consent, membrane status, fetal presentation, prior uterine surgery and fetal monitoring are not supplied by the number. It is not a self-examination aid or a reason to perform an examination without clinical indication.

Inputs used

  • Cervical dilation category documented at a clinician-performed examination.
  • Effacement percentage category, not an ultrasound cervical-length measurement.
  • Presenting-part station relative to the maternal ischial spines.
  • Cervical consistency and position from the same examination.

Clinical interpretation

NICE NG207 distinguishes scores of 6 or less from scores above 6 for induction-method decisions; its definition describes 8 or more as generally indicating cervical readiness. This tool therefore does not label 6 as favorable or collapse 7 into the highest-readiness group. None of these thresholds independently establishes a treatment, an induction start time or a safe route of birth.

Worked example

An examination with 1-2 cm dilation, 40-50% effacement, station -2, medium consistency and middle position contributes 1 + 1 + 1 + 1 + 1 = 5. If a later examination has the same categories except soft consistency and anterior position, the total becomes 7. That two-point change describes the selected findings; it does not establish a percentage chance of vaginal birth. The fully selected lowest categories total 0, while the highest categories total 13.

Limitations and safety notes

Examination categories are observer dependent, and the historical method does not include all determinants of induction outcome. Different Bishop modifications have different inputs or cutoffs. The accepted categorical observations must not be extrapolated to an unlisted station or interpolated across a gap. A low score is not a contraindication to medically indicated induction, and a high score cannot override maternal or fetal concerns. This is an arithmetic and source-based guide, not independent clinical validation or an endorsement by the cited organizations.

Frequently asked questions

Why is a score of 7 described separately?

An induction-method threshold and a general cervical-readiness description answer different questions. Keeping 7 separate prevents a threshold used in one clinical decision from becoming an unsupported guarantee of birth outcome.

References

  • https://pubmed.ncbi.nlm.nih.gov/14199536/
  • https://www.nice.org.uk/guidance/ng207/evidence/full-guideline-july-2008-pdf-9266823757
  • https://www.nice.org.uk/guidance/ng207/chapter/Recommendations

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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