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Modifying Cervical Bishop Scoring System

Bishop Score; Are Further Modifications Needed?

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT02314260
Enrollment
80
Registered
2014-12-11
Start date
2014-07-31
Completion date
2014-12-31
Last updated
2015-01-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Failed Induction of Labor

Keywords

labour induction, cervical length, trans-vaginal assessment of cervical length, Bishop score

Brief summary

To have an early more precise way to predict failed induction in patients undergoing elective termination of pregnancy & those more likely to undergo caesarian section,this will Spare patients with decreased chances of favorable induction a long and exhausting trial of labour with increased probability of complications and an emergency caesarian

Detailed description

After approval of the ethical & scientific committees of the OBGYN department of Kasr El Aini hospital, 80 primigravidas undergoing induction of labour at our hospital in a prospective blind study were subjected to history taking, examination, investigations & ultrasonography. Indication for pregnancy termination was explained to each patient and a written consent was obtained. Clinical examination & assessment: Patients were examined vaginally by the attending physician and a Bishop score was assigned and recorded according to the original bishop scoring system 1964 (Bishop EH, 1964) as seen in table 1. Table 1: The Bishop score (Bishop EH, 1964): 0 points : for no dilation, effacement 0-30%, station -3, firm consistency & posterior position of cervix 1. point : for dilation 1-2 cm, effacement 40-50%, station -2, medium consistency & mid position of cervix. 2. points: for dilation 3-4 cm, effacement 60-70%, station -1, soft consistency & Anterior position of cervix. 3. points: for dilation 5-6 cm, effacement 80%, station +1 or +2. Sum of the points in each criteria assessed will be the bishop score. Trans-vaginal ultrasound assessment of cervical length was performed using the same machine each time Sonoace x4 (samsung Medison Co., Ltd. Seoul, South Korea) following a standardized technique in which the bladder was emptied & the vaginal probe 6.5MHz was introduced into the vagina and manipulated so that the main anatomical landmarks (bladder, fetal presentation, cervical canal, internal and external cervical os) were identified. The hyper echoic line extending from the internal os to external os, was identified by fine manipulations of the probe. The cervical canal length was measured as the distance between the internal and external os, while presence of funneling was recorded. Funneling was defined as a (V)or (U) shaped indentation of the internal os. In the presence of funneling, the length of an associated funnel was not included as part of the cervical length, and the measurement was taken from the apex of the funnel to the external os. A modified bishop score was devised for the purpose of this study, which aimed to incorporate cervical length into the bishop scoring system. This score was calculated by addition or subtraction of the figure obtained respectively for cervical length in table 2 from the original bishop score. Table 2: Scoring System for respective cervical length Score: -2 for Cervical length \> 2.5cm by trans-vaginal ultrasound. Score: -1 for Cervical length 2 - 2.5 cm by trans-vaginal ultrasound. Score: 0 for Cervical length 1.6 - 1.9 cm by trans-vaginal ultrasound. Score: +1 for Cervical length 1 - 1.5 cm by trans-vaginal ultrasound. Score: +2 for Cervical length \< 1 cm by trans-vaginal ultrasound. We think an unfavorable score should decrease the value of the bishop score, and not just fail to increase it (in comparison to the original score) & hence our negative value for unfavorable cervical length. The values used to set the figures for the max and min score for cervical length in table 2 were based on our observation of how several studies displayed the range of their results for cervical length and how we think that it should impact the bishop score. There is no exact pre-set cut off value for what a favorable cervical length should be. Labour induction and Monitoring: Induction of labor was carried out as per our hospital's standard protocol, in which patients with unfavorable cervical examination i.e. bishop score of 4 or less were given dinoprostone 3mg (Dinoglandin E2 ® Egypharma Nasr City Cairo Egypt) vaginal tablet, with re-dosing intervals every six hours if no significant cervical changes were noted. In cases where the initial bishop score was 5 or more, or improvement was seen after dinoprostone, Oxytocin was initiated for induction. In cases already having one or more dinoprostone vaginal tablets, oxytocin was started four hours after the final dinoprostone dose, using the low-dose protocol beginning with 2 mU/min (and increase by 2 mU/min) at incremental time intervals (15 - 30 minutes). The goal was to reach satisfactory contractions (3-5 per ten minutes with each contraction lasting 45 seconds), & to avoid uterine hyperstimulation. All through induction & labor fetal heart rate was measured every 30 minutes in first stage of labor and every 10 minutes in second stage of labor. Progress of labor was observed & recorded, the total amount of oxytocin used, fetal weight and Apgar score for each baby were recorded. The total time taken till reaching active phase of labor, total time taken till delivery & mode of delivery were recorded. Any decision to proceed to caesarean was reviewed by a senior consultant and the indication was noted. Any case undergoing caesarean for any indication other than failure of progress will be omitted from the results.

Interventions

OTHERbishop score calculation

Assessment of bishop score by vaginal examination

trans-vaginal ultrasound assessment of cervical length.

OTHERModified bishop score calculation

using the cervical length and the original bishop score to calculate modified bishop score

Induction of labor was carried out as per our hospital's standard protocol.

Sponsors

Kasr El Aini Hospital
Lead SponsorOTHER

Study design

Observational model
CASE_ONLY
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Age
20 Years to 34 Years
Healthy volunteers
Yes

Inclusion criteria

1. Primigravida Singleton pregnancy with mature fetus at term indicated for termination of pregnancy. 2. Cephalic presentation. 3. Medical indications for termination of pregnancy e.g.: Pre-eclampsia, uncontrolled diabetes at term..e.t.c, 4. Post-term pregnancy. 5. Fetal indication: signs of fetal compromise e.g.: decreased biophysical profile, poor umbilical Doppler indices, diminished liquor. 6. premature rupture of membranes (PROM) not going into spontaneous labor within 24 hours since onset. 7. Intrauterine fetal death (IUFD).

Exclusion criteria

1. they had true labor pains or clear onset of labor as diagnosed by cervical changes. 2. Previous uterine surgery (scared uterus). 3. Cephalo-pelvic disproportion. 4. Mal-presentations 5. Severe oligo-hydramnios i.e.: amniotic fluid index Less than 5. 6. Twin pregnancy. 7. Fetal macrosomia. -Growth beyond a specific threshold (weight above 4000g) 8) Placenta previa. 9\) Fetal bradycardia in case of living fetus.

Design outcomes

Primary

MeasureTime frameDescription
Area Under Receiver Operating Characteristic Curve (ROC) for Modified Bishop Score5 monthsto predict failed induction and comparing it to the area under curve for bishop score to find out which test is more accurate in predicting caesarean section, The positive actual state is failed induction and performing Caesarean Section.The positive actual state is failed induction, the true positive rate (Sensitivity) is plotted in function of the false positive rate (100-Specificity). So as the numbers approaches 1, induction fails, the Y-axis of the curve is sensitivity and the x- axis is (1-specificity).

Secondary

MeasureTime frameDescription
Area Under Curve for The Bishop Score5 monthsto predict failed induction and comparing it to the area under curve for modified bishop score to find out which test is more accurate in predicting caesarean section, The positive actual state is failed induction and performing Caesarean Section. The positive actual state is failed induction, the true positive rate (Sensitivity) is plotted in function of the false positive rate (100-Specificity), So as the numbers approaches 1, induction fails, the Y-axis of the curve is sensitivity and the x- axis is (1-specificity).
Cut Off Value for The Modified Bishop Score5 monthsthe value at which there a high sensitivity and specificity to predict failed labour induction
Cut Off Value for Bishop Score5 monthsthe value at which there a high sensitivity and specificity to predict failed labour induction

Countries

Egypt

Participant flow

Recruitment details

started July 2014 till December 2014 & recruited 80 primigravidas undergoing scheduled for pregnancy termination at Kasr El Aini Hospital

Participants by arm

ArmCount
Labour Induction
80 primigravidas undergoing bishop score calculation, trans-vaginal ultrasound assessment of cervical length &, Modified bishop score calculation, then induction of labour at our hospital. bishop score calculation: Assessment of bishop score by vaginal examination Trans-vaginal ultrasound: trans-vaginal ultrasound assessment of cervical length. Modified bishop score calculation: using the cervical length and the original bishop score to calculate modified bishop score labour induction: Induction of labor was carried out as per our hospital's standard protocol.
80
Total80

Baseline characteristics

CharacteristicLabour Induction
Age, Continuous24.31 years
STANDARD_DEVIATION 3.65
Apgar score at 5 minutes8.45 units on a scale
STANDARD_DEVIATION 1.82
Bishop Score5.71 units on a scale
STANDARD_DEVIATION 1.2
Cervical Length2.06 Cm
STANDARD_DEVIATION 0.56
Fetal weight (kilograms)3.02 kilograms
STANDARD_DEVIATION 0.267
Gestational Age39.70 Weeks
STANDARD_DEVIATION 1.5
Induction to delivery time17.38 Hours
STANDARD_DEVIATION 4.29
New Modified Bishop Score5.28 units on a scale
STANDARD_DEVIATION 1.88
Region of Enrollment
Egypt
80 participants
rupture of membraned duration9.93 hours
STANDARD_DEVIATION 4.5
Sex: Female, Male
Female
80 Participants
Sex: Female, Male
Male
0 Participants
Time to active Phase11.87 Hours
STANDARD_DEVIATION 3.25

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
— / —
other
Total, other adverse events
0 / 80
serious
Total, serious adverse events
18 / 80

Outcome results

Primary

Area Under Receiver Operating Characteristic Curve (ROC) for Modified Bishop Score

to predict failed induction and comparing it to the area under curve for bishop score to find out which test is more accurate in predicting caesarean section, The positive actual state is failed induction and performing Caesarean Section.The positive actual state is failed induction, the true positive rate (Sensitivity) is plotted in function of the false positive rate (100-Specificity). So as the numbers approaches 1, induction fails, the Y-axis of the curve is sensitivity and the x- axis is (1-specificity).

Time frame: 5 months

Population: the area under the modified bishop score was 0.916 (95% \[confidence interval \] 0.85-0.97). The positive actual state is failed induction and performing Caesarean Section, So as the numbers approaches 1, induction fails, the Y-axis of the curve is sensitivity and the x- axis is (1-specificity).

ArmMeasureValue (NUMBER)
Labour InductionArea Under Receiver Operating Characteristic Curve (ROC) for Modified Bishop Score0.916 probability
Comparison: Null hypothesis: true area = 0.5 The positive actual state is failed induction, the true positive rate (Sensitivity) is plotted in function of the false positive rate (100-Specificity)p-value: 095% CI: [0.854, 0.979]t-test, 2 sided
Secondary

Area Under Curve for The Bishop Score

to predict failed induction and comparing it to the area under curve for modified bishop score to find out which test is more accurate in predicting caesarean section, The positive actual state is failed induction and performing Caesarean Section. The positive actual state is failed induction, the true positive rate (Sensitivity) is plotted in function of the false positive rate (100-Specificity), So as the numbers approaches 1, induction fails, the Y-axis of the curve is sensitivity and the x- axis is (1-specificity).

Time frame: 5 months

Population: The positive actual state is failed induction and performing Caesarean Section, So as the numbers approaches 1, induction of labour fails, the Y-axis of the curve is (sensitivity) and the x- axis is (1-specificity).

ArmMeasureValue (NUMBER)
Labour InductionArea Under Curve for The Bishop Score0.806 probability
Comparison: Null hypothesis: true area = 0.5 The positive actual state is failed induction, the true positive rate (Sensitivity) is plotted in function of the false positive rate (100-Specificity)p-value: 095% CI: [0.693, 0.919]t-test, 2 sided
Secondary

Cut Off Value for Bishop Score

the value at which there a high sensitivity and specificity to predict failed labour induction

Time frame: 5 months

Population: sensitivity of 83% \& specificity was 73% to failed induction

ArmMeasureValue (NUMBER)
Labour InductionCut Off Value for Bishop Score5.5 probability
Comparison: The smallest cutoff value is the minimum observed test value minus 1, and the largest cutoff value is the maximum observed test value plus 1. All the other cutoff values are the averages of two consecutive ordered observed test values.p-value: 095% CI: [0, 10]t-test, 2 sided
Secondary

Cut Off Value for The Modified Bishop Score

the value at which there a high sensitivity and specificity to predict failed labour induction

Time frame: 5 months

Population: sensitivity of 83% and a specificity of 87% for failed induction.

ArmMeasureValue (NUMBER)
Labour InductionCut Off Value for The Modified Bishop Score4.5 probability
Comparison: The smallest cutoff value is the minimum observed test value minus 1, and the largest cutoff value is the maximum observed test value plus 1. All the other cutoff values are the averages of two consecutive ordered observed test values.p-value: 095% CI: [0, 10]t-test, 2 sided

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026