Bishop score, also Bishop's score or cervix score, is a pre-labor scoring system to assist in predicting whether induction of labor will be required. It has also been used to assess the likelihood of spontaneous preterm delivery. The Bishop score was developed by Professor Emeritus of Obstetrics and Gynecology, Edward Bishop, and was first published in August 1964.

Components

The total score is calculated by assessing the following five components on manual vaginal examination by a trained professional: The Bishop score grades patients who would be most likely to achieve a successful induction. The duration of labor is inversely correlated with the Bishop score; “A Bishop score of 9 conveys a high likelihood for a successful induction. For research purposes, a Bishop score of 4 or less identifies an unfavorable cervix and may be an indication for cervical ripening.” Excerpt From Williams Obstetrics, 25th Edition F. Gary Cunningham, Kenneth J. Leveno, Steven L. Bloom, Jodi S. Dashe, Barbara L. Hoffman, Brian M. Casey and Catherine Y. Spong This material may be protected by copyright. They can be remembered with the mnemonic: Call PEDS For Parturition = Cervical Position, Effacement, Dilation, Softness; Fetal Station.

Scoring

The examiner assigns a score to each component of 0 to 2 or 0 to 3. The highest possible score is 13 and the lowest possible score is 0.

Interpretation

A score of 5 or less suggests that labour is unlikely to start on its own during the next few days. A score of 9 or more indicates that labour will most likely commence spontaneously in the next few days. Scores between 5 and 9 require additional consideration and professional judgement for clinical management. A Bishop's score 6 or less often indicates that induction (e.g., with controlled-release prostaglandin E2/prostin gel [Cervidil], intravaginal gel [Prostin], intracervical gel [Prepidil]) is unlikely to be successful. Some sources indicate that only a score of 8 or greater is reliably predictive of a successful induction. The score can be recalculated as the pregnancy progresses.

Modified Bishop score

According to the Modified Bishop's pre-induction cervical scoring system, effacement has been replaced by cervical length in cm, with scores as follows: 0 for >3 cm, 1 for >2 cm, 2 for >1 cm, 3 for >0 cm. Cervical length may be easier and more accurate to measure and have less inter-examiner variability. Another modification for the Bishop's score is the modifiers. Points are added or subtracted according to special circumstances as follows: