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Mechanical Dilation of the Cervix in a Scarred Uterus (MEDICS)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03471858
Recruitment Status : Unknown
Verified October 2019 by Soe-na Choo, Ministry of Health, Singapore.
Recruitment status was:  Recruiting
First Posted : March 21, 2018
Last Update Posted : October 8, 2019
Department of Obstetrics and Gynaecology, National University Hospital
Yong Loo Lin School of Medicine
National University Hospital, Singapore
National University, Singapore
Information provided by (Responsible Party):
Soe-na Choo, Ministry of Health, Singapore

Brief Summary:
To determine if mechanical labour induction can offer a safer and effective alternative to prostaglandins to women with previous caesarean section attempting trial of labour after caesarean (TOLAC).

Condition or disease Intervention/treatment Phase
Pregnancy Related Labor Complication Cesarean Section; Dehiscence Device: Cervical balloon Drug: Prostaglandins Not Applicable

Detailed Description:

There is good evidence to show that induction of labour with a transcervical balloon compares favourably with the use of prostaglandins.The cervical balloon works by softening & stretching the cervix mechanically & stimulates the release of endogenous prostaglandins.

When compared with prostaglandins, meta-analysis have shown that for TCB induction, there is no significant different in caesarean section rates (27% vs 25%) with a reduced risk of hyperstimulation with fetal heart rate change (0.4% vs 3%). Further, when compared against induction with misoprostol, induction with a Foley catheter balloon was found to have a lower rate of caesarean section for a non-reassuring fetal heart rate (RR 0.54, 95% CI 0.37-0.79) and a fewer vaginal instrumental deliveries (RR 0.74, 95% CI 0.55-0.95) [41]. One randomized controlled trial of 824 women with no previous caesarean section comparing foley catheter balloon with a prostaglandin E2 gel demonstrated no difference in caesarean section rates & 2 cases of uterine rupture or perforation in the prostaglandin E2 arm but not in the foley catheter balloon arm. Another study involving 1859 women comparing foley catheter balloon with oral misoprostol showed no difference in caesarean section rates or complications. It was, however, noted that induction with foley catheter balloon more likely required oxytocin induction at 80.3% vs 68.4% for misoprostol.

While there were earlier concerns of an increase in infectious morbidity when using mechanical induction of labour due to the presence of a foreign body, more recent RCTs & meta-analysis have shown that there is no significant increase.

One of the main concerns for induction of labour in patients with a previous uterine scar is an increased risk of uterine rupture. One observational study of 20,095 women quoted a risk of uterine rupture in spontaneous labour to be 0.52% & in prostaglandin-induced labour to be 0.77%. Another observational study involving 33,699 women quoted a risk of 0.4% and 1% respectively. While there are also studies which suggest that there is no significant increase in the rate of uterine rupture, many professional bodies have discouraged prostaglandin-induction in women with previous scars.

Due to lower levels of hyperstimulation that could lead to fetal distress or uterine rupture, trans cervical balloon induction has found itself as a possible, safer means of induction of labour for women who are keen for vaginal birth after caesarean and are agreeable with induction. Most RCTs were small in size & did not demonstrate any uterine rupture or dehiscence. However, 2 retrospective cohort studies involving a size of 2479 & 208 women respectively showed a uterine rupture rate of about 0.5%. trans cervical balloon induction appears to be a safe method for inducing consenting women keen for vaginal birth after caesarean and this study will contribute towards this body of evidence.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 100 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: MEchanical DIlatation of the Cervix in a Scarred Uterus (MEDICS)
Actual Study Start Date : February 14, 2019
Estimated Primary Completion Date : December 31, 2020
Estimated Study Completion Date : December 31, 2020

Arm Intervention/treatment
Active Comparator: Cervical Balloon
Transcervical 2-way 18 French (18F) single balloon Foley catheter, applied using a sponge-holding forceps into the cervical canal with the balloon inflated to a minimum of 30ml and maximum of 60ml with sterile water or saline [1]. This will be administered once during the study and will be retained for a maximum of 12 hours within the 24 hour study period.
Device: Cervical balloon
To assess if a cervical balloon catheter (foleys catheter) for mechanical induction of labour is comparable to prostaglandin usage for induction of labour in women who have had a previous caesarean section.
Other Name: Foley Balloon Catheter

Active Comparator: Prostaglandin
Prostaglandin E2 (Prostin®) 3mg tablet, placed high in the vaginal fornix. This will be administered per vaginum once in the first 6 hours; a second dose is administered at the discretion of the clinician / clinical team 6 hours after the first pessary, for a cumulative total of 6mg within the 24 hour study period.
Drug: Prostaglandins
Prostin will be used in the control arm.
Other Name: Prostin

Primary Outcome Measures :
  1. Improvement in Bishops score [ Time Frame: 24hours ]
    Assess for increase in Bishops score from baseline of <5 (Unfavourable) to >6

Secondary Outcome Measures :
  1. Achieving active labour [ Time Frame: Within 24-48hours of intervention ]
    Achieving delivery

  2. Number of PGE tablets required [ Time Frame: Within 24-48hours of intervention ]
    For the prostin arm - How many tablets required, ie 1 or 2 to achieve improvement in Bishops score

  3. Number of times the foley catheter (cervical balloon) needs to be readjusted [ Time Frame: Within 24-48hours of intervention ]
    Numerical number of the times the foley catheter needs to be removed, replaced or readjusted

  4. Mode of delivery [ Time Frame: Within 24-48hours of intervention ]
    Successful vaginal birth after previous caesarean section, or emergency caesarean section

  5. Maternal complications [ Time Frame: Within 24-48hours of intervention ]
    failed device insertion, inability to void urine following insertion, intolerance of device and early removal, vaginal bleeding after insertion of device, spontaneous membrane rupture.

  6. Fetal complications [ Time Frame: Within 24-48hours of intervention ]
    fetal distress, meconium-stained liquor, malpresentation, neonatal Apgar score of <7 at 5 minutes, cord blood pH of ≤7.0, admission to NICU, neonatal hypoxic-ischaemic encephalopathy, neonatal death.

  7. Infectious complications [ Time Frame: Within 24-48hours of intervention ]
    intrauterine infection, maternal sepsis (e.g. endometritis, UTI), neonatal sepsis, maternal pyrexia, onset of antibiotics

  8. Labour complications [ Time Frame: Within 24-48hours of intervention ]
    uterine hyperstimulation (i.e. >5 contractions / 10mins with abnormal CTG), placental abruption, cord prolapse, postpartum haemorrhage, 3rd / 4th degree perineal tears, uterine rupture.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   Female
Gender Based Eligibility:   Yes
Gender Eligibility Description:   Pregnant females
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Female ≥ 21 years of age at booking visit
  • 1 previous uncomplicated lower segment caesarean section (CS)
  • Aiming for TOLAC
  • Written informed consent (and assent when applicable) obtained from subject or subject's legal representative and ability for subject to comply with the requirements of the study
  • Singleton pregnancy
  • Gestational age >37 weeks
  • Understands risk of TOLAC
  • Eligible for induction of labour for the standard obstetric indications, including post-date or post-term pregnancies at 40-41 completed weeks of gestation
  • Unfavourable Bishop's Score ≤ 5 requiring cervical priming
  • Previous uterine surgery, including simple myomectomy, where there is no contraindication to TOLAC
  • Reactive CTG pre-induction
  • Ruptured membranes

Exclusion Criteria:

  • Refusal to participate
  • Women with 2 or more previous CS
  • Previous classical or lower segment vertical incision, or inverted T or J incision in the previous caesarean delivery
  • Previous uterine surgery with contra-indication to future TOLAC
  • Maternal contraindication for vaginal delivery
  • Fetal contraindication for vaginal delivery or major fetal abnormality
  • Malpresentation or cord presentation
  • Placenta praevia <20mm from internal os
  • Chorioamnionitis
  • Antepartum haemorrhage of undetermined origin AND deemed a contraindication for TOLAC
  • Suspected fetal macrosomia (estimated weight on ultrasound >4kg) AND deemed a contraindication for TOLAC
  • Congenital uterine abnormality
  • Multifetal pregnancy
  • Latex allergy or poorly-controlled asthma

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03471858

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Contact: Choo Soe-na, Dr
Contact: Citra Mattar, Dr +6567725555

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National University Hospital, Singapore Recruiting
Singapore, Singapore, 679973
Contact: Citra Mattar, Dr    67725555      
Sponsors and Collaborators
Ministry of Health, Singapore
Department of Obstetrics and Gynaecology, National University Hospital
Yong Loo Lin School of Medicine
National University Hospital, Singapore
National University, Singapore
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Soe-na Choo, Medical Officer, Ministry of Health, Singapore Identifier: NCT03471858    
Other Study ID Numbers: 2018/00248
First Posted: March 21, 2018    Key Record Dates
Last Update Posted: October 8, 2019
Last Verified: October 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Keywords provided by Soe-na Choo, Ministry of Health, Singapore:
caesarean, uterus
Additional relevant MeSH terms:
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Obstetric Labor Complications
Pregnancy Complications