Cervical dilation | <1 cm 1 - 2 cm 2-4 cm >4 cm |
Cervical effacement | 0 - 30% 40 - 50% 60-70% >= 80% |
Cervical consistency | Firm Intermediate Soft |
Cervical position | Posterior Intermediate Anterior |
Fetal station | -3 cm -2 cm -1 or 0 cm +1 or +2 cm |
The Bishop Score is a clinical scoring system based upon vaginal examination that assists in predicting whether induction of labor will be needed.
A modification of this was made by Calder, et al in 1974 (Modified Bishop Score).
5 components on vaginal exam are used:
The score can range from 0 to 13.
I. Cervical dilation
II. Cervical effacement
III. Cervical consistency
IV. Cervical position
V. Fetal station
Interpretation:
The lower the score, the less likely labor will start spontaneously. A score of <5 indicates that labor will not likely commence spontaneously. Scores of 9 or more are consistent with labor likely to commence with no induction.
Reference:
Bishop EH. Pelvic scoring for elective induction. Obstet Gynecol. 1964;24:266-8.
Calder AA, et al. Exta-amniotic prostaglandin E2 for the induction of labour at term. Journal of Obstetrics & Gynaecology of the British Commonwealth. 1974;81:39-46.