Impact of a Bladder Flap on Cesarean Scar Niche Development

NCT07634679 | Not Yet Recruiting DMC

• 1 other identifier: 2025-17472
• Study Type: interventional
• Target: 130
• Locations: 1 country
• Sites: 2

Brief Summary

The goal of this trial is to examine if the completion or omission of a bladder flap impacts the location and formation of cesarean scar niche in women undergoing primary cesarean section. The main question it aims to answer is if omission of a bladder flap changes the prevalence of cesarean scar niche on a 6-8 week postpartum ultrasound. Researchers will compare participants that have a bladder flap made to those that have a bladder flap omitted at time of their primary cesarean delivery. Participants will have routine postpartum care and be asked to return for a 6-8 week postpartum transvaginal ultrasound.

Conditions

Cesarean Scar Defect (Isthmocele)

Outcome Measures

Primary Outcomes (1)

• Presence of cesarean scar niche

  A dichotomous measure of the presence or absence of a cesarean scar niche, as defined by a residual myometrial thickness of \<3mm at the scar level, detected on transvaginal ultrasound. The presence of a cesarean scar niche increases risk for gynecologic complaints and abnormal placentation in subsequent pregnancies.

  From enrollment to transvaginal ultrasound, completed approximately 6-8 weeks postpartum

Secondary Outcomes (7)

• Distance of cesarean scar niche from internal os

  From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

• Size of cesarean scar niche

  From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

• Measurement of residual myometrium

  From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

• Size of cesarean scar defect in subsequent pregnancy

  From time of enrollment to time of subsequent pregnancy, up to 5 years following baseline pregnancy

• Cases of abnormal placentation in subsequent pregnancies

  From time of enrollment to time of subsequent pregnancy, up to 5 years following baseline pregnancy

Study Arms (2)

Bladder flap omission

NO INTERVENTION

Participants randomized to this arm will have the bladder flap step omitted prior to low transverse hysterotomy formation. Participants will not need to alter their postoperative or postpartum care.

Bladder flap formation

EXPERIMENTAL

Participants randomized to this arm will have a bladder flap formed using standard procedure during the cesarean delivery prior to low transverse hysterotomy and delivery of the infant. As with the 'Bladder flap omission' arm, participants will not need to alter their postoperative or postpartum care.

Procedure: Bladder flap formation

Interventions

Bladder flap formation PROCEDURE

Participants in this arm will have a bladder flap completed at the time of their cesarean delivery.

Bladder flap formation

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 years or older
• Primary low transverse cesarean section performed at Montefiore Weiler or Wakefield Hospitals
• Able to provide informed consent in English or Spanish
• Plan for postpartum care at Montefiore Medical Center

You may not qualify if:

• History of a prior uterine surgery
• Known congenital uterine anomalies
• Inability to safely access lower uterine segment at time of delivery
• Hysterotomy is extended past/outside the lower uterine segment at time of surgery
• Hysterectomy is indicated prior to postpartum follow-up

Sponsors & Collaborators

• Montefiore Medical Center: lead

Study Sites (2)

Jack D. Weiler Hospital - Einstein Campus

The Bronx, New York, 10461, United States

Location

Montefiore Einstein Hospital - Wakefield Campus

The Bronx, New York, 10466, United States

Location

Related Publications (11)

• Kamel R, Thilaganathan B. Time to reconsider elective Cesarean birth. Ultrasound Obstet Gynecol. 2021 Mar;57(3):363-365. doi: 10.1002/uog.22158. No abstract available.

  PMID: 33220003 BACKGROUND

• Kamara M, Henderson JJ, Doherty DA, Dickinson JE, Pennell CE. The risk of placenta accreta following primary elective caesarean delivery: a case-control study. BJOG. 2013 Jun;120(7):879-86. doi: 10.1111/1471-0528.12148. Epub 2013 Feb 28.

  PMID: 23448347 BACKGROUND

• Shi XM, Wang Y, Zhang Y, Wei Y, Chen L, Zhao YY. Effect of Primary Elective Cesarean Delivery on Placenta Accreta: A Case-Control Study. Chin Med J (Engl). 2018 Mar 20;131(6):672-676. doi: 10.4103/0366-6999.226902.

  PMID: 29521289 BACKGROUND

• O'Neill HA, Egan G, Walsh CA, Cotter AM, Walsh SR. Omission of the bladder flap at caesarean section reduces delivery time without increased morbidity: a meta-analysis of randomised controlled trials. Eur J Obstet Gynecol Reprod Biol. 2014 Mar;174:20-6. doi: 10.1016/j.ejogrb.2013.12.020. Epub 2013 Dec 22.

  PMID: 24411951 BACKGROUND

• Tuuli MG, Odibo AO, Fogertey P, Roehl K, Stamilio D, Macones GA. Utility of the bladder flap at cesarean delivery: a randomized controlled trial. Obstet Gynecol. 2012 Apr;119(4):815-21. doi: 10.1097/AOG.0b013e31824c0e12.

  PMID: 22395144 BACKGROUND

• Fukuda M, Fukuda K, Shimizu T, Bujold E. Ultrasound Assessment of Lower Uterine Segment Thickness During Pregnancy, Labour, and the Postpartum Period. J Obstet Gynaecol Can. 2016 Feb;38(2):134-40. doi: 10.1016/j.jogc.2015.12.009. Epub 2016 Mar 2.

  PMID: 27032737 BACKGROUND

• Rorie DK, Newton M. Histologic and chemical studies of the smooth muscle in the human cervix and uterus. Am J Obstet Gynecol. 1967 Oct 15;99(4):466-9. doi: 10.1016/0002-9378(67)90292-x.

  PMID: 4167498 BACKGROUND

• Kamel R, Eissa T, Sharaf M, Negm S, Thilaganathan B. Position and integrity of uterine scar are determined by degree of cervical dilatation at time of Cesarean section. Ultrasound Obstet Gynecol. 2021 Mar;57(3):466-470. doi: 10.1002/uog.22053.

  PMID: 32330331 BACKGROUND

• Klein Meuleman SJM, Min N, Hehenkamp WJK, Post Uiterweer ED, Huirne JAF, de Leeuw RA. The definition, diagnosis, and symptoms of the uterine niche - A systematic review. Best Pract Res Clin Obstet Gynaecol. 2023 Aug;90:102390. doi: 10.1016/j.bpobgyn.2023.102390. Epub 2023 Jul 15.

  PMID: 37506497 BACKGROUND

• Jauniaux E, Collins S, Burton GJ. Placenta accreta spectrum: pathophysiology and evidence-based anatomy for prenatal ultrasound imaging. Am J Obstet Gynecol. 2018 Jan;218(1):75-87. doi: 10.1016/j.ajog.2017.05.067. Epub 2017 Jun 24.

  PMID: 28599899 BACKGROUND

• Angolile CM, Max BL, Mushemba J, Mashauri HL. Global increased cesarean section rates and public health implications: A call to action. Health Sci Rep. 2023 May 18;6(5):e1274. doi: 10.1002/hsr2.1274. eCollection 2023 May.

  PMID: 37216058 BACKGROUND

Study Officials

• Pe'er Dar, MD

  Montefiore Medical Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Alyssa Yeung, MD

CONTACT

574-329-8771; ayeung@montefiore.org

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants will be randomized in a 1:1 ratio into two treatment groups one undergoing bladder flap formation and the other undergoing bladder flap omission

Study Record Dates

• First Submitted: June 4, 2026
• First Posted: June 9, 2026
• Study Start: June 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): May 1, 2032
• Last Updated: June 9, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: Beginning 6 months after trial publication for a period of up to 5 years.
• Access Criteria: Requests will require a data use agreement and a proposal review by the study team.

Locations

US (2)