Plain English Summary
Background and study aims
An induced labour is one that is started artificially, for example when the baby is overdue. Induction of labour when the cervix (neck of the womb) is not adequately prepared can lead to a longer labour compared to when labour commences naturally. To increase the success of labour induction, it is essential that the cervix is ready or "favourable". The methods of induction of labour are generally divided into two categories: using hormones (vaginal medication containing hormones) which can prepare the cervix before labour, and using a dilation device (cervix dilator with no hormones) which stimulates the body's natural hormones to prepare the cervix before labour. Dilation methods have been shown to work as well as hormonal methods. Dilation methods have also been shown to have improved outcomes for mother and baby when compared to hormonal methods. The aim of this study is to find out whether the mechanical cervical dilator Dilapan-S is an acceptable, safe way to induce labour.
Who can participate?
Women in their first pregnancy with no complications who are scheduled for induction of labour
What does the study involve?
Eligible patients fulfilling the study criteria on weekdays (Monday to Friday inclusive) are approached for study participation and offered induction with Dilapan-S or routine induction of labour with Propess. Those who opt for routine care and eligible women receiving Propess at weekends are used as the control group. Women who have a closed cervix and are therefore unable to have Dilapan-S instead receive Propess. Dilapan-S or Propess are inserted into the cervix and left in place for up to 24 hours before reassessment, unless removal is clinically indicated before this time. If the cervix is still unfavorable at reassessment, up to two prostin gels are used. Labour outcomes are recorded and compared between the two treatments.
What are the possible benefits and risks of participating?
Dilapan-S is a proven, safe mechanical cervical dilator. Dilation methods have also been shown to have improved outcomes for mother and baby when compared to hormonal methods in previous studies.
Where is the study run from?
National Maternity Hospital (Ireland)
When is the study starting and how long is it expected to run for?
May 2017 to November 2017
Who is funding the study?
OLM Ltd (provided Dilapan-S free of charge)
Who is the main contact?
Dr David Crosby
A prospective comparative trial of Dilapan-S compared with Propess for induction of labor at 41+ weeks in nulliparous pregnancy
To determine whether mechanical induction with Dilapan-S is an acceptable, safe method of induction of labor in post-dates uncomplicated nulliparous pregnancy.
National Maternity Hospital Dublin Ethics Committee, May 2017
Preliminary prospective comparative pilot study
Primary study design
Secondary study design
Non randomised study
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet
Obstetrics: induction of labor
Eligible patients fulfilling study criteria on weekdays (Monday to Friday inclusive) were approached for study participation. Study participation was induction with Dilapan-S versus routine induction of labor with Propess. Between Monday and Fridays, n=26 of eligible women approached agreed to Dilapan-S and n=22 number opted for routine care. Those who opted for routine care and eligible women receiving Propess at weekends (n=4) were used as the control group. Administration of Dilapan-S or Propess was by the clinician assigned to the antenatal ward on the day of study. If women had a closed cervix and therefore unable to have Dilapan-S, Propess was administered. Analysis was by intention-to-treat.
Between 1 and 5 Dilapan-S rods were inserted into the cervix by the clinician depending on the Bishop’s Score of the cervix as per manufacturer’s instructions. Dilapan-S rods were left in situ for up to 24 hours prior to reassessment, unless removal was clinically indicated prior to this time. If the cervix was still unfavorable at reassessment, up to two prostin (Intracervical PGE2) gels were used.
Propess (Dinoprostone 10mg)
Propess was inserted into the posterior fornix of the cervix as per manufacturer’s instructions. Propess pessary was left in situ for up to 24 hours prior to reassessment as per hospital policy, unless removal was clinically indicated prior to this time. If the cervix was still unfavorable at reassessment, up to two prostin (Intracervical PGE2) gels were used.
Primary outcome measures
1. Compliance with study protocol, quantified as the proportion of women who agreed to study participation and who completed the trial protocol of insertion of Dilapan-S. This occurred at time of insertion of the product
2. Safety: Maternal infection defined as maternal temperature greater than 38⁰C, endometritis, chorioamnionitis or antibiotic usage following study allocation until delivery of baby
3. Safety: Maternal hyperstimulation defined as > 7 contractions in 15 minutes at any time following study allocation until delivery of baby
4. Safety: Neonatal infection defined as fever, suspected or proven sepsis, or need for antibiotic use in the first 72 hours of life
5. Safety: Neonatal Apgar scores at 1 and 5 minutes of life
Secondary outcome measures
1. Change in Bishop’s score pre and post-induction (within 24 hours of insertion of induction agent)
2. Complications associated with induction agent (within 24 hours of insertion of induction agent):
2.1. Cervical injury
2.2. Bleeding during insertion or removal
2.3. Spontaneous expulsion
2.4. Retraction into cavity
2.5. Dilator entrapment
2.6. Dilator fragmentation
2.7. Rupture of membranes
3. Median duration from induction to delivery in minutes
4. Median duration of induction agent in situ in minutes
5. Delivery within 24 hours of receiving induction of labor method
6. Cesarean delivery rate
7. Instrumental delivery rate
8. Additional use of prostaglandin (1 or 2 doses) after reassessment following removal of initial product (Dilapan-S or Dinoprostone)
9. Additional use of oxytocin for labour induction or augmentation
10. Epidural use in labor
11. 3rd and 4th degree tears
12. Manual removal of placenta
13. Postpartum hemorrhage > 1L and post-partum blood transfusion (within 72 hours of delivery)
14. Meconium at delivery
15. Neonatal intensive care unit (NICU) admission (within 72 hours of delivery)
Overall trial start date
Overall trial end date
Participant inclusion criteria
1. Pregnant women in their first pregnancy (nulliparous women)
2. Adequate English to understand the purpose of the study
3. Scheduled for induction of labor for post-dates (≥41 weeks gestation)
4. Unfavorable cervix defined as Bishops Score ≤6
5. Not suitable for artificial rupture of membranes (ARM)
Target number of participants
Participant exclusion criteria
1. Any pre-existing medical condition or medical condition of pregnancy
2. Pathological CTG prior to induction
3. Oligohydramnios on post-dates scan
4. 2 or more LLETZ treatments
5. Maternal age <18 years old or >40 years old
6. Body mass index ≥30kg/m2
7. Women with a closed cervix, insertion was not possible and so were unable to receive Dilapan-S
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
National Maternity Hospital
OLM Ltd (provided Dilapan-S free of charge)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Submitted to a high impact peer reviewed journal with intent to publish the findings in the next year.
IPD sharing statement
The datasets generated during and/or analysed during the current study is not expected to be made available due to data protection issues.
Intention to publish date
Participant level data
Not expected to be available
Results - basic reporting