Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12609000186257
Ethics application status
Approved
Date submitted
6/02/2009
Date registered
17/04/2009
Date last updated
5/07/2012
Type of registration
Retrospectively registered

Titles & IDs
Public title
Caesarean Section Following Induction of Labour in Nulliparous Women with an Unfavourable Cervix: a Comparison of Three Ripening Agents - PGE2 Gel, Single or Double Balloon Catheter
Scientific title
Induction of labour in nulliparous women with an unfavourable cervix: A Randomised Controlled Trial of Prostaglandin E2 Intravaginal Gel, a Double Balloon Catheter (Atard Ripener Device (ARD)) and the Foley Catheter
Universal Trial Number (UTN)
Trial acronym
The Balloon Trial
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Induction of labour in nulliparous women with unfavourable cervix 4277 0
Condition category
Condition code
Reproductive Health and Childbirth 4506 4506 0 0
Fetal medicine and complications of pregnancy

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
1.Foley single balloon catheter inserted above the internal cervical os, and filled with 30mls of sterile water. The catheter is strapped to the inner aspect of one leg on slight tension. The catheter will be removed after 12 hours if spontaneous expulsion had not occurred.
or
2.Double balloon catheter inserted through the cervix and the balloons either side of the cervix inflated with 80mls of water.
Intervention code [1] 4005 0
Treatment: Drugs
Intervention code [2] 4006 0
Treatment: Devices
Comparator / control treatment
Prostaglandin E2 gel (dinoprostone, 2mg in 3g, ProstinE2, Pfizer Australia) placed into the posterior fornix of the vagina. This will be repeated six hourly up to a maximum of three doses unless the Bishop score is greater than six or regular painful contractions less than 5 minutes apart had commenced.
Control group
Active

Outcomes
Primary outcome [1] 5388 0
% with caesarean section.
Timepoint [1] 5388 0
completion of labour
Secondary outcome [1] 9055 0
Indications for caesarean section:
1. non-reassuring fetal status defined as fetal heart rate patterns (FHR) showing reduced baseline variability, late decelerations and/or complicated variable decelerations 2. failed induction defined as inability to rupture membranes after 3 doses of PGE2; or 12 hours of mechanical ripening; or cervical dilatation < 4cm after 8 hours of strong contractions.
Timepoint [1] 9055 0
completion of labour
Secondary outcome [2] 9056 0
time from induction to delivery
Timepoint [2] 9056 0
completion of labour
Secondary outcome [3] 9057 0
Adverse reactions to ripening agents:
1. Uterine hyperstimulation defined as >=5 contractions in 10 minutes for 2 consecutive 10-minute periods or a contraction lasting at least 2 minutes with or without changes in FHR patterns.
2. Inability to tolerate mechanical device defined as patient discomfort or inability to void leading to removal of mechanical device
3. Placental abruption
4. Postnatal infection
5. Hospital readmission during the puerperium
Timepoint [3] 9057 0
discharge from hospital
Secondary outcome [4] 9058 0
Patient satisfaction assessed using visual analogue scales (VAS):
1. Overall satisfaction with induction of labour
2. Pain on insertion of ripening device or gel
3. Pain during cervical ripening
Timepoint [4] 9058 0
48 hours after birth

Eligibility
Key inclusion criteria
Nulliparous women.
Over 36 weeks’ gestation.
Singleton fetus in cephalic presentation. Intact membranes.
Modified Bishop score of 0 to 4
Minimum age
16 Years
Maximum age
No limit
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Previous uterine surgery
Low-lying placenta
Any active or purulent infection of the lower vaginal tract
Abnormal pre-induction fetal heart rate (FHR) tracing

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Women will be given information about the trial when the decision is made for induction of labour.
Informed consent will be obtained on admission to the delivery ward.
Treatment allocation - Each participant will select an opaque envelope from a selection of 12 envelopes in which the mode of induction is allocated
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computerised random number generation
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Stratification for fetal fibronectin status (positive, negative, not done)
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
20/08/2001
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
330
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 4461 0
Charities/Societies/Foundations
Name [1] 4461 0
Women and Infants Research Foundation
Country [1] 4461 0
Australia
Primary sponsor type
University
Name
The University of Western Australia
Address
School of Women's and Infants' Health
M550
35 Stirling Highway
Crawley
Western Australia 6009
Country
Australia
Secondary sponsor category [1] 4020 0
Charities/Societies/Foundations
Name [1] 4020 0
Women and Infants Research Foundation
Address [1] 4020 0
King Edward Memorial Hospital
374 Bagot Road
Subiaco
Western Australia 6008
Country [1] 4020 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 6519 0
Womens and Childrens Health Service
Ethics committee address [1] 6519 0
King Edward Memorial Hospital for Women
GPO Box D184
PERTH WA 6840
Ethics committee country [1] 6519 0
Australia
Date submitted for ethics approval [1] 6519 0
Approval date [1] 6519 0
17/05/2001
Ethics approval number [1] 6519 0
620/EW

Summary
Brief summary
One quarter of labours are induced due to either maternal or fetal reasons in the Western World. Unfortunately, not all of these inductions are successful, and a failed induction of labour usually results in a caesarean section.
The most useful predictor of success for an induction of labour is the assessment of the cervix (neck of womb) prior to the induction of labour. A firm, closed cervix (unfavourable cervix) increases the likelihood of a failed induction of labour and a caesarean section.
A number of different techniques have been utilised to improve the success rates of induction of labour when the cervix is unfavourable. These include hormone infusions (oxytocin), intravaginal gels and tablets (prostaglandin E2, misoprostol) and mechanical techniques for ripening cervixes.
With an unfavourable cervix, the caesarean section rate with hormone infusions is 50%. The use of intravaginal prostaglandin E2 reduces the caesarean section rate to 30%, and this is currently the routine technique for induction of labour when the cervix is unfavourable.
Mechanical ripening of the cervix with balloon catheters has been investigated over the last 10 years using both single and double balloon catheters. The single balloon catheter has been found to be at least as effective as prostaglandin E2 vaginal gel. Several small clinical trials have suggested that a double balloon catheter may be more effective at cervical ripening and induction of labour, lowering the caesarean section rate for failed induction of labour.
The specific aim of this project is to compare the standard induction of labour technique utilised for women with an unfavourable (closed, tight) cervix, which is intravaginal prostaglandin E2, with induction of labour with the single balloon Foley catheter and with a double balloon catheter.
It is hypothesised that the double balloon catheter will be more effective at cervical ripening than prostaglandin E2 or the Foley single balloon catheter, reducing the number of caesarean sections for failed induction of labour without increasing the number of caesarean sections for non-reassuring fetal heart rate patterns.
In this trial, we plan to recruit 330 women who deliver at King Edward Memorial Hospital, and to randomise them to one of three groups
Group 1: Standard induction of labour with vaginal prostaglandin E2
Group 2: Induction of labour with the single balloon Foley catheter
Group 3: Induction of labour with the ARD double balloon catheter

The potential significance of this trial is that we hope to prove that the new double balloon catheter technique will reduce the caesarean section rate in women who are having an induction of labour from 30% with the standard induction of labour technique, to 15% with the new technique. Reducing the caesarean rate has short, intermediate, and long-term benefits. The short-term benefits include reduced operative morbidity and shorter hospital stay. The intermediate benefits include improved maternal wellbeing during the first month post delivery by avoiding a major abdominal operation. The long term benefits include easier options with subsequent pregnancy as labour is less complicated if the mother has not had a previous caesarean section. Avoiding caesarean sections also reduces the incidence of low-lying placentas and placentas which grow into previous uterine scars which increases the risk of hysterectomy with subsequent pregnancies.
Trial website
Trial related presentations / publications
1.Induction of Labour with an Unfavourable Cervix: “The Balloon Trial”. Pennell CE, Jewell M, Doherty DA, Dickinson JE. Am J Obstetrics and Gynecology December 2003, 189 (6), Volume 189, A546. Abstract
Public notes

Contacts
Principal investigator
Name 29255 0
Address 29255 0
Country 29255 0
Phone 29255 0
Fax 29255 0
Email 29255 0
Contact person for public queries
Name 12502 0
Dr Craig Pennell
Address 12502 0
School of Women’s and Infants’ Health (M550),
The University of Western Australia,
35 Stirling Hwy, Crawley
Western Australia, 6009
Country 12502 0
Australia
Phone 12502 0
+61 8 9340 1330
Fax 12502 0
+ 61 8 9381 3031
Email 12502 0
[email protected]
Contact person for scientific queries
Name 3430 0
Dr Craig Pennell
Address 3430 0
School of Women’s and Infants’ Health (M550),
The University of Western Australia,
35 Stirling Hwy, Crawley
Western Australia, 6009
Country 3430 0
Australia
Phone 3430 0
+61 8 9340 1330
Fax 3430 0
+ 61 8 9381 3031
Email 3430 0
[email protected]

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No Supporting Document Provided



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