Bishop Score Calculator

What is the Bishop score?

The Bishop score is a pre-labor scoring system used to assess how “favorable” the cervix is for induction of labor. It combines five findings from a vaginal examination:

• Cervical dilation – how open the cervix is (in centimeters).
• Cervical effacement or length – how thinned or shortened the cervix is.
• Fetal station – how low the baby’s presenting part is in the pelvis.
• Cervical consistency – whether the cervix feels firm, medium, or soft.
• Cervical position – whether the cervix is posterior, mid-position, or anterior.

Each parameter is assigned 0–3 points. The total Bishop score ranges from 0 to 13. Higher scores indicate a more favorable cervix and a higher likelihood that an induction of labor will result in vaginal delivery.

How to interpret the Bishop score

Interpretation can vary slightly between guidelines, but commonly:

• 0–3 points: Very unfavorable cervix. Induction is less likely to succeed without prior cervical ripening.
• 4–5 points: Unfavorable cervix. Induction may be possible but often requires cervical ripening and may take longer.
• 6–7 points: Intermediate. Some protocols consider ≥6 as “favorable enough,” but success still depends on other factors.
• ≥8 points: Favorable cervix. Higher chance of successful induction and vaginal delivery.

The Bishop score is only one part of the decision-making process. Maternal and fetal conditions, indication for induction, parity, and local protocols are equally important.

Classic vs. modified Bishop score

The original Bishop score used effacement as a percentage. Many modern protocols use a modified Bishop score that replaces effacement with cervical length in centimeters, which can be easier to measure consistently:

• ≥3 cm length → 0 points
• 2–2.9 cm → 1 point
• 1–1.9 cm → 2 points
• ≤0.9 cm → 3 points

This calculator lets you switch between the classic (effacement %) and a length-based version so you can match the documentation style used in your setting.

Limitations and clinical considerations

• The Bishop score is subjective and depends on the examiner’s experience.
• It does not account for all factors that influence induction success (parity, BMI, indication, fetal size, etc.).
• Different institutions may use slightly different cutoffs or modified scoring systems.
• A low score does not mean vaginal delivery is impossible; it suggests that cervical ripening and a longer induction process may be needed.

Always interpret the Bishop score in context and follow your local guidelines and supervising clinician’s recommendations.

Frequently asked questions

Is a Bishop score of 6 good?

A score of 6 is often considered “borderline favorable.” Some protocols use ≥6 as a threshold for induction, while others prefer ≥8. With a score of 6, induction may still be successful, but the process can be longer and may require cervical ripening.

How often is the Bishop score checked?

There is no universal schedule. It is usually assessed before deciding on induction and may be rechecked during the induction process if progress is uncertain. Repeated vaginal examinations should be minimized to reduce discomfort and infection risk, especially after membrane rupture.

Can the Bishop score predict when spontaneous labor will start?

Not precisely. A higher Bishop score suggests that the body is closer to spontaneous labor, but it cannot accurately predict the exact timing. Some people with low scores go into labor soon, while others with higher scores may still take time.

Safety note

This Bishop score calculator is for educational and reference purposes only. It cannot replace a professional medical evaluation, diagnosis, or treatment. Only a qualified clinician can perform the examination and decide on induction of labor. If you are pregnant and have questions about induction or your Bishop score, discuss them with your obstetrician or midwife.