The Bishop Score Calculator estimates how ready (or “ripe”) a woman’s cervix is for labour induction. Introduced by Edward Bishop in 1964, it combines five findings from a vaginal examination into a single number that predicts whether inducing labour is likely to lead to a successful vaginal delivery.
How it works
Five cervical and fetal parameters are each scored and summed. Three parameters score 0–3 and two score 0–2, for a maximum total of 13:
- Dilation — 0 (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 (relative to ischial spines) — −3 = 0, −2 = 1, −1/0 = 2, +1/+2 = 3.
- Consistency — firm = 0, medium = 1, soft = 2.
- Position — posterior = 0, mid = 1, anterior = 2.
The total maps to an interpretation: ≥8 favourable (induction likely to succeed), 6–7 intermediate, and ≤5 unfavourable (cervical ripening is usually recommended first).
Example and notes
A cervix that is 3 cm dilated (2), 70% effaced (2), at station −1 (2), soft (2),
and anterior (2) scores 2 + 2 + 2 + 2 + 2 = 10, which is favourable. A closed,
firm, posterior cervix at station −3 scores near 0 and signals the need for
ripening.
The Bishop score guides but does not dictate management. A higher score correlates with a shorter induction and a lower caesarean risk, but clinical context — gestational age, indication for induction, and maternal preference — always informs the final decision.