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Bishop Score (Cervical Ripeness for Induction)

The Bishop score (0–13) rates cervical dilation, effacement, consistency, position and fetal station to predict successful induction of labour. A score >8 means vaginal delivery after induction is about as likely as with spontaneous labour; ≤6 is unfavourable and usually warrants cervical ripening.

Dilation: Closed (0 cm) (0); 1–2 cm (1); 3–4 cm (2); ≥ 5 cm (3)
Effacement: 0–30% (0); 40–50% (1); 60–70% (2); ≥ 80% (3)
Fetal station: −3 (0); −2 (1); −1 or 0 (2); +1 or +2 (3)
Cervical consistency: Firm (0); Medium (1); Soft (2)
Cervical position: Posterior (0); Mid-position (1); Anterior (2)

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Interpretation

Result	Meaning
≤ 6	Unfavourable; consider cervical ripening (prostaglandin, balloon)
7–8	Intermediate
> 8	Favourable; likelihood of vaginal delivery similar to spontaneous labour

Formula

Dilation: closed 0, 1–2 cm 1, 3–4 cm 2, ≥5 cm 3 · Effacement: 0–30% 0, 40–50% 1, 60–70% 2, ≥80% 3 · Station: −3 0, −2 1, −1/0 2, +1/+2 3 · Consistency: firm 0, medium 1, soft 2 · Position: posterior 0, mid 1, anterior 2

Clinical pearls

Dilation carries the most predictive weight; a simplified Bishop score (dilation, effacement, station) performs similarly.
Thresholds differ: ACOG describes >8 as favourable and ≤6 as unfavourable.

Examples

bishop 3 cm, 60% effaced, station -1, soft, anterior bishop score closed cervix, 30% effaced, -3 station, firm, posterior is the cervix favorable: 2cm 50% -2 medium mid

FAQ

What Bishop score is favourable for induction?

A score above 8 is favourable: the chance of vaginal delivery is similar to spontaneous labour. A score of 6 or less is unfavourable and cervical ripening is usually used first.

What is the maximum Bishop score?

13 points: dilation, effacement and station score up to 3 each; consistency and position up to 2 each.

Evidence

Bishop EH. Pelvic scoring for elective induction. Obstet Gynecol 1964;24:266–8.

Pediatrics & Obstetrics · Reviewed 2026-10-14 · Methodology