Impact of a Bladder Flap on Cesarean Scar Niche Development (B-FIND)

June 4, 2026 updated by: Montefiore Medical Center
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.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

As the rate of cesarean deliveries increases globally, the importance of a cesarean scar niche (CSN) has evolved into a significant clinical concern with long term obstetric and gynecologic implications including increasing risk for placenta accreta spectrum (PAS) in future pregnancies and abnormal uterine bleeding. In fact, the main cause of PAS is placentation into uterine scars secondary to cesarean deliveries

Bladder flap formation is a standard step in cesarean deliveries and involves dissecting the bladder off the uterus to push it inferiorly to allow better access to the lower uterine segment for hysterotomy and decrease risk of bladder injury. The lower uterine segment is targeted for hysterotomy as it has been shown that the proportion of muscle tissue and the thickness of the wall of the uterus increases as one travels from the cervix to the fundus. Therefore, by making an incision in the lower uterine segment, the surgeon has less tissue to go through to deliver the fetus and disrupts less muscle to preserve uterine myometrial integrity. While studies have suggested bladder flap omission in primary cesarean deliveries does not increase intraoperative complications and reduces operating time. CSN assessment was not an outcome evaluated in these studies and the decision to omit or perform a bladder flap is at the discretion of the surgeon.

Previous studies have looked at different surgical techniques and different cervical dilations at time of cesarean delivery and the impact on niche formation and location. There has been no consensus on hysterotomy or other surgical techniques to decrease risk of CSN formation. To our knowledge, there have not been studies that have assessed postoperative CSN in relation to completion or omission of a bladder flap prior to hysterotomy. As such, the investigator team hypothesizes that omission of a bladder flap lends itself to a more cephalad hysterotomy and potentially more clinically significant CSNs.

Study Type

Interventional

Enrollment (Estimated)

130

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • New York
      • The Bronx, New York, United States, 10461
        • Jack D. Weiler Hospital - Einstein Campus
        • Contact:
      • The Bronx, New York, United States, 10466
        • Montefiore Einstein Hospital - Wakefield Campus
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Bladder flap omission
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.
Experimental: Bladder flap formation
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
Participants in this arm will have a bladder flap completed at the time of their cesarean delivery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Presence of cesarean scar niche
Time Frame: From enrollment to transvaginal ultrasound, completed approximately 6-8 weeks postpartum
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 Outcome Measures

Outcome Measure
Measure Description
Time Frame
Distance of cesarean scar niche from internal os
Time Frame: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
Sonographic distance of cesarean scar niche from internal cervical os, measured in millimeters, on postpartum transvaginal ultrasound. The investigator team hypothesizes that a scar further from the internal os has increased risk for abnormal placentation in future pregnancies.
From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
Size of cesarean scar niche
Time Frame: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
Sonographic dimensions of length and width of cesarean scar niche, measured in mm, on transvaginal ultrasound. The investigator team hypothesizes that larger niches are associated with increased risk of abnormal placentation in future pregnancies and increased risk of future gynecologic complaints.
From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
Measurement of residual myometrium
Time Frame: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
Sonographic measurement of residual myometrium in mm by transvaginal ultrasound. Thinner residual myometrium may imply a larger defect, increased risk for abnormal placentation or formation of a uterine window in future pregnancies.
From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
Size of cesarean scar defect in subsequent pregnancy
Time Frame: From time of enrollment to time of subsequent pregnancy, up to 5 years following baseline pregnancy
Sonographic measurement of dimensions (length and width) of cesarean scar defect in subsequent pregnancy, measured in mm, to assess if larger postpartum niches are associated with larger defects in subsequent pregnancies as they may carry increased risk of morbidity in the pregnancy.
From time of enrollment to time of subsequent pregnancy, up to 5 years following baseline pregnancy
Cases of abnormal placentation in subsequent pregnancies
Time Frame: From time of enrollment to time of subsequent pregnancy, up to 5 years following baseline pregnancy
If encountered in a subsequent pregnancy, the number of cases of abnormal placentation in the cesarean scar and placenta accreta spectrum will be summarized. Ultrasound evidence of placenta accreta spectrum include disappearance of the border between placenta and myometrium, placental lacunae, increased vasculature from placenta extending into myometrium, abnormal invasion of placenta into surrounding organs and structures. Pathology will be used to confirm the number of cases of placenta accreta spectrum.
From time of enrollment to time of subsequent pregnancy, up to 5 years following baseline pregnancy
Uterine Position/Flexion
Time Frame: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
As an anteverted and retroflexed uterus is commonly the result of a cesarean delivery and scar tissue altering anatomical position, the clinicians will observe if a bladder flap alters position of the uterus. At the 6 week transvaginal ultrasound, the position of the uterus as anteverted or retroverted and flexion as anteflexed or retroflexed will be recorded. In the sagittal plane on transvaginal ultrasound, if the cervix appears on the viewer's right or left, the position is anteverted or retroverted, respectively. The anterior or posterior flexion of the fundus will define anteflexion and retroflexion, respectively
From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
Number/percentage of Operative and Postoperative Complications
Time Frame: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum
Patient charts will be reviewed to summarize the number/percentage of surgical complications in each arm. This includes complications such as damage to surrounding structures, hemorrhage, hematoma formation, surgical site infections.
From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Montefiore Medical Center

Investigators

  • Principal Investigator: Pe'er Dar, MD, Montefiore Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

May 1, 2032

Study Registration Dates

First Submitted

June 4, 2026

First Submitted That Met QC Criteria

June 4, 2026

First Posted (Actual)

June 9, 2026

Study Record Updates

Last Update Posted (Actual)

June 9, 2026

Last Update Submitted That Met QC Criteria

June 4, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 2025-17472

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data (IPD) that underlie the results reported in future publications will be made available to qualified researchers upon request

IPD Sharing Time Frame

Beginning 6 months after trial publication for a period of up to 5 years.

IPD Sharing Access Criteria

Requests will require a data use agreement and a proposal review by the study team.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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