🤰 Bishop Score Calculator

Inducing labor works best when the cervix is already preparing: softening, thinning, opening, and moving forward. The Bishop score grades those five changes, dilation, effacement, station, consistency, and position, into a 13-point total that predicts whether induction will succeed.

Scores of 8 or more mean a favorable cervix with induction success near spontaneous-labor rates; 5 or below means an unfavorable cervix where ripening first is strongly advised. This calculator scores the five components from the vaginal exam.

How to use this calculator

Score each component from the most recent cervical exam.

The five components

Each component captures one aspect of cervical readiness:

Dilation, effacement, and station carry the most weight because they most directly reflect labor progress. A soft, anterior cervix with the head low scores well even before much dilation.

Worked example

Dilation 3 cm (2), effacement 60% (2), station -1 (2), soft consistency (2), anterior position (2). Total: 10. Favorable: induction has success rates approaching spontaneous labor, and oxytocin can start directly.

Contrast: closed (0), 20% effaced (0), station -3 (0), firm (0), posterior (0). Total: 0. Deeply unfavorable: induction now would likely fail, so cervical ripening or waiting is the plan.

Ripening an unfavorable cervix

Scores of 6 or below usually trigger cervical ripening before oxytocin. Prostaglandins (dinoprostone, misoprostol) soften and thin the cervix chemically; balloon catheters (Foley) dilate it mechanically. Both roughly double the chance of vaginal delivery compared to oxytocin alone on an unripe cervix.

Ripening takes hours, sometimes overnight, which surprises families expecting induction to mean "baby today." The wait is the treatment: a ripe cervix makes everything downstream faster and safer. For related pregnancy tools, see our due date calculator and Apgar score guide for what follows delivery.

Beyond the score

The Bishop score predicts induction success, not the need for induction. The decision to induce weighs gestational age, maternal conditions (preeclampsia, diabetes), fetal concerns, and patient preference. A favorable cervix makes induction reasonable; it does not make it necessary.

Modified versions add parity and other factors, and ultrasound cervical length offers an objective alternative. But the bedside Bishop endures because it is free, immediate, and good enough to guide the ripening decision.

Induction methods compared

Once the Bishop score is known, the method follows. Each induction tool suits a different cervix:

Combinations are common: balloon overnight, then oxytocin in the morning, with amniotomy once dilation allows. The Bishop score decides the opening move; progress exams decide the rest. Unfavorable scores that ignore ripening and jump to oxytocin are the classic setup for a long, discouraging induction.

Do not forget the low-tech option: membrane sweeping in the clinic can nudge an intermediate cervix toward favorability and sometimes starts labor outright, especially after 39 weeks. It is uncomfortable but drug-free, and a successful sweep can spare a formal induction entirely. Sweeping works best when the cervix is already softening, which is another way of saying the Bishop score predicts its success too.

What the ARRIVE trial changed

For decades, elective induction before 41 weeks was discouraged without a medical reason. Then the ARRIVE trial randomized over 6,000 first-time mothers to induction at 39 weeks versus waiting, and found the induction group had fewer cesareans and no worse newborn outcomes. Guidelines shifted: elective induction at 39 weeks became a reasonable choice, not a forbidden one.

The Bishop score sits at the center of that choice. ARRIVE participants had favorable-enough cervixes on average, and critics note the results may not extend to deeply unfavorable scores. A 39-week induction with a Bishop of 9 is a different proposition than with a Bishop of 2, which is why counseling now pairs the trial's findings with the individual's exam.

The practical upshot: the conversation moved from "should we induce early" to "given your cervix, your history, and your preferences, what is the best plan." The score did not become less important; it became the personalization tool for a decision the trial made legitimate.

Shared decision-making is the real product of ARRIVE: the trial gave patients a legitimate choice, and the Bishop score, parity, and personal priorities fill in the answer. Some choose induction for the scheduling certainty and the known hospital team; others choose waiting for spontaneity. Both are defensible with a favorable cervix, and neither should be pressured.

For informational purposes only, not medical advice. Consult a healthcare professional.