Cesarean Scar Defect (Isthmococele)NCT07611331
Single-Layer Versus Double-Layer Uterine Closure After Primary Cesarean Section
A study testing Double-layer hysterorrhaphy at primary cesarean section and Single-layer hysterorrhaphy at primary cesarean section in people with Cesarean Scar Defect (Isthmococele) and Pelvic Pain, run by Hédi Chaker Hospital at 1 site in Tunisia.
Trial summary
This study compares two surgical techniques for closing the uterus after cesarean section: single-layer versus double-layer closure. The primary objective is to determine which technique results in better uterine scar healing, measured by residual myometrial thickness (RMT) and cesarean scar defect (niche) prevalence… Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Cesarean Scar Defect (Isthmococele), Pelvic Pain, Spotting
- What is being tested?
- Double-layer hysterorrhaphy at primary cesarean section and Single-layer hysterorrhaphy at primary cesarean section
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 384 participants
- Where
- 1 siteTunisia
- Study dates
- 1 Jan 2025to 30 Apr 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Women aged 18 years or older
- Singleton pregnancy
- Gestational age ≥ 37 weeks (term pregnancy)
- Scheduled or emergency primary cesarean section (first cesarean delivery, no previous uterine scar)
- Low transverse uterine incision (Pfannenstiel or Joel-Cohen approach)
- Ability to provide written informed consent
- Willingness to attend follow-up visits at 6 weeks and 6 months postoperatively
- Patient affiliated to a social security system or equivalent healthcare coverage
Who cannot join
- Previous uterine surgery (prior cesarean section, myomectomy, uterine perforation, or any procedure leaving a uterine scar)
- Multiple pregnancy (twins or higher-order multiples)
- Preterm delivery (gestational age < 37 weeks)
- Classical (vertical) or inverted T uterine incision
- Placenta previa or placenta accreta spectrum disorder
- Active uterine infection or chorioamnionitis at time of surgery
Show all 13Show fewer
- Coagulation disorders or anticoagulant therapy
- Immunosuppressive therapy or conditions affecting wound healing (systemic corticosteroids, immunosuppressants)
- Severe maternal comorbidities (uncontrolled diabetes, connective tissue disorders, chronic renal failure)
- Participation in another interventional clinical trial
- Patient unable to attend scheduled follow-up visits
- Patient unable to understand or sign informed consent
- Fetal demise or major fetal malformation
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Single-Layer Versus Double-Layer Uterine Closure After Primary Cesarean Section: Impact on Residual Myometrial Thickness and Cesarean Scar Defect Formation - A Prospective Randomized Controlled Trial
This study compares two surgical techniques for closing the uterus after cesarean section: single-layer versus double-layer closure. The primary objective is to determine which technique results in better uterine scar healing, measured by residual myometrial thickness (RMT) and cesarean scar defect (niche) prevalence at 6 weeks and 6 months postoperatively.
BACKGROUND:
Read more
Cesarean section is one of the most common surgeries worldwide. After fetal delivery, the uterine incision must be closed by suture. Poor scar healing can lead to niche formation, abnormal bleeding, pelvic pain, dyspareunia, and complications in future pregnancies including uterine rupture and placenta accreta.
INTERVENTION:
Participants are randomized 1:1 to receive either:
- Single-layer closure: one continuous non-locking suture through full myometrial thickness
- Double-layer closure: two successive extra-mucosal non-locking sutures excluding the decidua
ASSESSMENTS:
Transvaginal ultrasound at 6 weeks and 6 months measures RMT and niche presence. Standardized symptom questionnaires assess pelvic pain, spotting, dysmenorrhea, and dyspareunia.
ELIGIBILITY:
Women aged 18-45 years undergoing primary cesarean section with singleton pregnancy at term (gestational age ≥ 37 weeks).
ENROLLMENT: 384 participants (192 per group)
SETTING: Department of Obstetrics and Gynecology, Hedi Chaker University Hospital, Sfax, Tunisia
FOLLOW-UP: 6 months per participant in which the patients attend 2 follow-up visits:
First visit 6 weeks after surgery. Second visit at 6 months after surgery
.And have a pelvic ultrasound at each visit
Read the detailed description
BACKGROUND AND RATIONALE
Cesarean section is one of the most commonly performed surgical procedures worldwide. After fetal delivery, the uterine incision must be closed by suture using one of two accepted techniques: single-layer or double-layer closure. Despite widespread use of both methods : no consensus exists regarding which technique produces superior long-term uterine scar healing.
Poor scar healing can result in a niche. formation (isthmocele), defined as a triangular anechoic indentation of the anterior uterine wall at the scar site with depth greater than or equal to 2 mm (Jordan et al., 2019). Niches occur in 25-70% of women after cesarean section and are associated with postmenstrual spotting, chronic pelvic pain, dyspareunia, fertility impairment, and serious obstetric complications in future pregnancies, including placenta accreta spectrum and uterine rupture.
The residual myometrial thickness (RMT) is the primary ultrasound marker of scar healing quality, defined as the minimum myometrial thickness at the scar site. An RMT below 2.5 mm is associated with a substantially increased risk of uterine rupture in subsequent pregnancies.
Previous studies comparing single-layer and double-layer closure have been limited by heterogeneous populations including scarred uteri, non-standardized surgical techniques, inconsistent ultrasound protocols, and insufficient sample sizes. No study has focused exclusively on primary cesarean sections with a fully standardized operative protocol.
SURGICAL TECHNIQUES
Single-Layer Closure (Group A): The uterine incision is closed with one continuous non-locking suture incorporating the full thickness of the myometrium in one pass, including the decidua.
Double-Layer Closure (Group B): The uterine incision is closed with two successive non-locking extra-mucosal sutures, excluding the decidua. Layer 1 approximates the inner half of the myometrium. Layer 2 buries the first layer, incorporating the outer half of the myometrium and uterine serosa.
All other operative steps are strictly standardized across both groups.
ULTRASOUND ASSESSMENT PROTOCOL
Transvaginal ultrasound (TVUS) is performed by blinded trained sonographers using Samsung HS40 with EVN4-9 probe (4-9 MHz), with empty bladder, preferably in the follicular phase (Day 7-14 of the menstrual cycle), in the mid-sagittal plane.
RMT is measured perpendicular to the serosa at the thinnest scar point. Adjacent myometrial thickness (AMT) is measured 5-10 mm from the scar on both sides. The myometrial ratio is calculated as RM (%) = RMT/AMT x 100.
Niche dimensions (depth, length, width) and volume (ellipsoid formula) are recorded when present.
RANDOMIZATION
Participants are randomized 1:1 using the Clinical Trial Randomization Tool with permuted blocks of variable sizes (4, 6, and 8). Allocation is revealed to the operating surgeon immediately before hysterorrhaphy, after fetal and placentaldelivery. Participants and ultrasound assessors are blinded to group allocation.
STATISTICAL ANALYSIS
Primary analysis uses multiple linear regression for RMT and binary logistic regression for niche prevalence, adjusted for age, BMI, gestational age, uterine exteriorization, surgeon category, and cesarean indication.
Advanced analyses include linear mixed-effects models for repeated measures, Firth penalized logistic regression for predictive modeling, counterfactual mediation analysis (Imai et al.) with bootstrap validation (10,000 replications), inverse probability weighting for loss to follow-up, and five-scenario multiple imputation (MICE).
Software: SPSS v26.0 and R v4.3. Reporting: CONSORT 2010 guidelines.
ETHICAL CONSIDERATIONS
This trial is conducted in accordance with the Declaration of Helsinki (2013), ICH-GCP E6(R2), and Tunisian national regulations. Ethical approval was obtained from the Ethics Committee of the Faculty of Medicine of Sfax (Approval No. 31/26). All participants provide written informed consent. Participation is voluntary and withdrawal is permitted at any time without consequence to medical care.
- Conditions
- Cesarean Scar Defect (Isthmococele), Pelvic Pain, Spotting, Amenorrhea Secondary, Metrorrhagia
- Being tested
- Double-layer hysterorrhaphy at primary cesarean section, Single-layer hysterorrhaphy at primary cesarean section
- Keywords
- single layer, double layer, Residual Myometrial Thickness (RMT), Ultrasound, Isthmocele-niche, Cesarean, Scar healing
- Medical subject headings
- Pelvic Pain, Metrorrhagia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Double-layer hysterorrhaphy at primary cesarean sectionProcedure or surgery
Also called Two-layer uterine closure, Double-layer uterine closure, HDP technique
After fetal and placental delivery, the uterine incision is closed in two layers using continuous absorbable suture (polyglactin 910). Layer 1: running suture approximating the full myometrial thickness. Layer 2: continuous imbricating suture reinforcing the first layer and improving hemostasis. Additional reinforcement sutures placed if needed. Aims to optimize uterine scar healing and reduce cesarean scar defect (niche) formation.
Single-layer hysterorrhaphy at primary cesarean sectionProcedure or surgery
Also called One-layer uterine closure, Single-layer uterine closure, HPU technique
After fetal and placental delivery, the uterine incision is closed in one single layer using a continuous absorbable suture (polyglactin 910) approximating the full myometrial thickness in a running pattern. No second reinforcement layer is performed. Additional reinforcement sutures are placed if needed. This represents the conventional standard technique for uterine closure at cesarean section.
| Study group | Role | What they receive |
|---|---|---|
| Single-layer Uterine Closure (HPU) | Active comparator | Participants allocated to this arm undergo primary cesarean section with single-layer uterine closure (hysterorrhaphy). After fetal and placental extraction, the uterine incision is closed in one single layer using a continuous absorbable suture (polyglactin 910 or equivalent), which approximates the myometrium in a running unlocked pattern. No second imbricating layer is performed. Additional interrupted sutures (reinforcement stitches) may be placed if necessary for bleeding control. All participants are followed postoperatively with standardized transvaginal ultrasound assessments at 6 weeks and 6 months to evaluate residual myometrial thickness (RMT) and cesarean scar defect (niche) development, as well as clinical symptom monitoring. Receives: Procedure: Single-layer hysterorrhaphy at primary cesarean section |
| Double-layer Uterine Closure (HDP) | Experimental | articipants allocated to this arm undergo primary cesarean section with double-layer uterine closure (hysterorrhaphy). After fetal and placental extraction, the uterine incision is closed in two distinct layers using a continuous absorbable suture (polyglactin 910 or equivalent). The first layer approximates the myometrium with a running unlocked suture. The second layer invaginates the first using a continuous suture to reinforce the closure and improve hemostasis. Additional interrupted sutures (reinforcement stitches) may be placed if necessary for bleeding control. All participants are followed postoperatively with standardized transvaginal ultrasound assessments at 6 weeks and 6 months to evaluate residual myometrial thickness (RMT) and cesarean scar defect (niche) development, as well as clinical symptom monitoring. Receives: Procedure: Double-layer hysterorrhaphy at primary cesarean section |
What is being measured
The primary outcome is the main question the study is designed to answer.
Residual Myometrial Thickness (RMT) at the Cesarean Scar at 6 Weeks and 6 Months
Residual myometrial thickness (RMT) measured in millimeters at the thinnest point of the uterine scar using standardized transvaginal two-dimensional ultrasound, performed by blinded sonographers according to the protocol of Naji et al. (2012). RMT compared between single-layer (HPU) and double-layer (HDP) closure groups at 6 weeks and 6 months postoperatively.
Measured: 6 weeks and 6 months after cesarean section
Prevalence of Cesarean Scar Defect (Niche) at 6 Weeks and 6 Months Postoperatively
Cesarean scar defect (niche) defined as a hypoechoic triangular indentation at the site of the uterine incision with depth ≥ 2mm or residual myometrial thickness (RMT)/adjacent myometrial thickness (AMT) ratio < 50%, detected by standardized transvaginal two-dimensional ultrasound. Prevalence compared between single-layer (HPU) and double-layer (HDP) closure groups at 6 weeks and 6 months postoperatively.
Measured: 6 weeks and 6 months after cesarean section
Secondary outcomes (9)
Prevalence of Gynecological Symptoms Related to Cesarean Scar Defect
Assessment of symptoms potentially related to uterine scar defect including: postmenstrual spotting, menometrorrhagia, dysmenorrhea, chronic pelvic pain, dyspareunia, urinary symptoms, and abnormal uterine bleeding at day 10 postoperatively. Symptoms assessed by standardized clinical questionnaire at 6 weeks and 6 months. Compared between HPU and HDP groups.
Measured: Day 10, 6 weeks, and 6 months after cesarean section
Identification of Independent Risk Factors for Cesarean Scar Defect Formation
Identification of independent risk factors for cesarean scar defect (niche) at 6 weeks and 6 months using multivariate logistic regression analysis. Variables assessed include: closure technique, operative duration, use of reinforcement sutures, uterine position, BMI, parity, type of cesarean section (elective vs emergency), and cervical dilation at time of surgery.
Measured: 6 weeks and 6 months after cesarean section
Cesarean Scar Defect Linear Dimensions
Length, width, and depth of detected cesarean scar defect measured in millimeters by transvaginal ultrasound at 6 weeks and 6 months. Unit of Measure: Millimeters (mm)
Measured: 6 weeks and 6 months after cesarean section
Cesarean Scar Defect Volume
Estimated volume of cesarean scar defect calculated using ellipsoid formula: V(mm³) = (π/6) × Length × Width × Depth Unit of Measure: Cubic millimeters (mm³)
Measured: 6 weeks and 6 months post-cesarean
Operative Duration of Hysterorrhaphy and Total Cesarean Section
Measurement of time (minutes and seconds) required for uterine closure (hysterorrhaphy duration) and total operative time from skin incision to skin closure. Number of suture materials used and frequency of additional reinforcement sutures also recorded. Compared between HPU and HDP groups.
Measured: preoperative (during cesarean section procedure)
Intraoperative Complications Rate
Rate of intraoperative complications including hemorrhage requiring transfusion, bladder injury, ureteral injury, and unintended uterine incision extension. Unit of Measure: Number of events (n) and percentage (%)
Measured: Perioperative : During cesarean section procedure
Postoperative Infectious Complications Rate
Rate of postoperative infectious complications including endometritis, surgical site infection, and urinary tract infection, assessed during hospitalization and at 6-week visit. Unit of Measure: Number of events (n) and percentage (%)
Measured: Up to 6 weeks after cesarean section
Hospital Length of Stay
Number of days from cesarean section to hospital discharge. Unit of Measure: Days
Measured: Up to 5 days after cesarean section
Blood Transfusion Requirement
Number of packed red blood cell units transfused during hospitalization. Unit of Measure: Number of units
Measured: Up to 5 days after cesarean section
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 May 2026
- Study start1 Jan 2025
- Primary completion1 Jan 2026
- Study completion30 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Cesarean Scar Defect (Isthmococele)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- A prospective, randomized, parallel-group trial comparing two uterine closure techniques during primary cesarean section. Participants were randomized in a 1:1 ratio to receive either single-layer hysterorrhaphy (HPU) or double-layer hysterorrhaphy (HDP). Blinding was maintained for the ultrasound evaluators. Uterine scar quality (RMT and niche prevalence) and clinical symptoms are assessed at 6 weeks and 6 months post-surgery.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 384 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hédi Chaker Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Larbi Nizar, Hédi Chaker Hospital
- Investigators
- Derbel Mohamed, Professor, Principal investigator, Department of obstetric and gynaecology of Hedi Chaker sfaxKhanfir Fatma, Professor, Principal investigator, Department of obstetric and gynaecology of Hedi Chaker sfax
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07611331
- Sponsor's protocol ID
- 31/26
- Status last verified
- May 2026
- First submitted
- 9 May 2026
- Last updated
- 28 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared publicly due to patient confidentiality requirements and institutional regulations. Aggregate results will be published in peer-reviewed journals.
Publications
Bij de Vaate AJ, van der Voet LF, Naji O, Witmer M, Veersema S, Brolmann HA, Bourne T, Huirne JA. Prevalence, potential risk factors for development and symptoms related to the presence of uterine niches following Cesarean section: systematic review. Ultrasound Obstet Gynecol. 2014 Apr;43(4):372-82. doi: 10.1002/uog.13199.
PubMed 23996650Di Spiezio Sardo A, Saccone G, McCurdy R, Bujold E, Bifulco G, Berghella V. Risk of Cesarean scar defect following single- vs double-layer uterine closure: systematic review and meta-analysis of randomized controlled trials. Ultrasound Obstet Gynecol. 2017 Nov;50(5):578-583. doi: 10.1002/uog.17401. Epub 2017 Oct 9.
PubMed 28070914Roberge S, Demers S, Berghella V, Chaillet N, Moore L, Bujold E. Impact of single- vs double-layer closure on adverse outcomes and uterine scar defect: a systematic review and metaanalysis. Am J Obstet Gynecol. 2014 Nov;211(5):453-60. doi: 10.1016/j.ajog.2014.06.014. Epub 2014 Jun 6.
PubMed 24912096Stegwee SI, Ben AJ, El Alili M, van der Voet LF, de Groot CJM, Bosmans JE, Huirne JAF; 2Close study group. Cost-effectiveness of single-layer versus double-layer uterine closure during caesarean section on postmenstrual spotting: economic evaluation alongside a randomised controlled trial. BMJ Open. 2021 Jul 2;11(7):e044340. doi: 10.1136/bmjopen-2020-044340.
PubMed 34215598Jordans IPM, de Leeuw RA, Stegwee SI, Amso NN, Barri-Soldevila PN, van den Bosch T, Bourne T, Brolmann HAM, Donnez O, Dueholm M, Hehenkamp WJK, Jastrow N, Jurkovic D, Mashiach R, Naji O, Streuli I, Timmerman D, van der Voet LF, Huirne JAF. Sonographic examination of uterine niche in non-pregnant women: a modified Delphi procedure. Ultrasound Obstet Gynecol. 2019 Jan;53(1):107-115. doi: 10.1002/uog.19049.
PubMed 29536581
Study at a glance
From the registry record, last updated by the sponsor on 28 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Single-Layer Versus Double-Layer Uterine Closure After Primary Cesarean Section: Impact on Residual Myometrial Thickness and Cesarean Scar Defect Formation - A Prospective Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07611331
- Acronym / sponsor ID
- 31/26
- Conditions
- Cesarean Scar Defect (Isthmococele), Pelvic Pain, Spotting, Amenorrhea Secondary, Metrorrhagia
- Keywords
- single layer, double layer, Residual Myometrial Thickness (RMT), Ultrasound, Isthmocele-niche, Cesarean, Scar healing
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 384 participants (actual)
- Lead sponsor
- Hédi Chaker HospitalUniversity, hospital or other
- Study start
- 1 Jan 2025 (actual)
- Primary completion
- 1 Jan 2026 (actual)
- Study completion
- 30 Apr 2026 (actual)
- First posted
- 28 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study compares two surgical techniques for closing the uterus after cesarean section: single-layer versus double-layer closure. The primary objective is to determine which technique results in better uterine scar healing, measured by residual myometrial thickness (RMT) and cesarean scar defect (niche) prevalence at 6 weeks and 6 months postoperatively.
BACKGROUND:
Cesarean section is one of the most common surgeries worldwide. After fetal delivery, the uterine incision must be closed by suture. Poor scar healing can lead to niche formation, abnormal bleeding, pelvic pain, dyspareunia, and complications in future pregnancies including uterine rupture and placenta accreta.
INTERVENTION:
Participants are randomized 1:1 to receive either:
- Single-layer closure: one continuous non-locking suture through full myometrial thickness
- Double-layer closure: two successive extra-mucosal non-locking sutures excluding the decidua
ASSESSMENTS:
Transvaginal ultrasound at 6 weeks and 6 months measures RMT and niche presence. Standardized symptom questionnaires assess pelvic pain, spotting, dysmenorrhea, and dyspareunia.
ELIGIBILITY:
Women aged 18-45 years undergoing primary cesarean section with singleton pregnancy at term (gestational age ≥ 37 weeks).
ENROLLMENT: 384 participants (192 per group)
SETTING: Department of Obstetrics and Gynecology, Hedi Chaker University Hospital, Sfax, Tunisia
FOLLOW-UP: 6 months per participant in which the patients attend 2 follow-up visits:
First visit 6 weeks after surgery. Second visit at 6 months after surgery
.And have a pelvic ultrasound at each visit
Detailed description
BACKGROUND AND RATIONALE
Cesarean section is one of the most commonly performed surgical procedures worldwide. After fetal delivery, the uterine incision must be closed by suture using one of two accepted techniques: single-layer or double-layer closure. Despite widespread use of both methods : no consensus exists regarding which technique produces superior long-term uterine scar healing.
Poor scar healing can result in a niche. formation (isthmocele), defined as a triangular anechoic indentation of the anterior uterine wall at the scar site with depth greater than or equal to 2 mm (Jordan et al., 2019). Niches occur in 25-70% of women after cesarean section and are associated with postmenstrual spotting, chronic pelvic pain, dyspareunia, fertility impairment, and serious obstetric complications in future pregnancies, including placenta accreta spectrum and uterine rupture.
The residual myometrial thickness (RMT) is the primary ultrasound marker of scar healing quality, defined as the minimum myometrial thickness at the scar site. An RMT below 2.5 mm is associated with a substantially increased risk of uterine rupture in subsequent pregnancies.
Previous studies comparing single-layer and double-layer closure have been limited by heterogeneous populations including scarred uteri, non-standardized surgical techniques, inconsistent ultrasound protocols, and insufficient sample sizes. No study has focused exclusively on primary cesarean sections with a fully standardized operative protocol.
SURGICAL TECHNIQUES
Single-Layer Closure (Group A): The uterine incision is closed with one continuous non-locking suture incorporating the full thickness of the myometrium in one pass, including the decidua.
Double-Layer Closure (Group B): The uterine incision is closed with two successive non-locking extra-mucosal sutures, excluding the decidua. Layer 1 approximates the inner half of the myometrium. Layer 2 buries the first layer, incorporating the outer half of the myometrium and uterine serosa.
All other operative steps are strictly standardized across both groups.
ULTRASOUND ASSESSMENT PROTOCOL
Transvaginal ultrasound (TVUS) is performed by blinded trained sonographers using Samsung HS40 with EVN4-9 probe (4-9 MHz), with empty bladder, preferably in the follicular phase (Day 7-14 of the menstrual cycle), in the mid-sagittal plane.
RMT is measured perpendicular to the serosa at the thinnest scar point. Adjacent myometrial thickness (AMT) is measured 5-10 mm from the scar on both sides. The myometrial ratio is calculated as RM (%) = RMT/AMT x 100.
Niche dimensions (depth, length, width) and volume (ellipsoid formula) are recorded when present.
RANDOMIZATION
Participants are randomized 1:1 using the Clinical Trial Randomization Tool with permuted blocks of variable sizes (4, 6, and 8). Allocation is revealed to the operating surgeon immediately before hysterorrhaphy, after fetal and placentaldelivery. Participants and ultrasound assessors are blinded to group allocation.
STATISTICAL ANALYSIS
Primary analysis uses multiple linear regression for RMT and binary logistic regression for niche prevalence, adjusted for age, BMI, gestational age, uterine exteriorization, surgeon category, and cesarean indication.
Advanced analyses include linear mixed-effects models for repeated measures, Firth penalized logistic regression for predictive modeling, counterfactual mediation analysis (Imai et al.) with bootstrap validation (10,000 replications), inverse probability weighting for loss to follow-up, and five-scenario multiple imputation (MICE).
Software: SPSS v26.0 and R v4.3. Reporting: CONSORT 2010 guidelines.
ETHICAL CONSIDERATIONS
This trial is conducted in accordance with the Declaration of Helsinki (2013), ICH-GCP E6(R2), and Tunisian national regulations. Ethical approval was obtained from the Ethics Committee of the Faculty of Medicine of Sfax (Approval No. 31/26). All participants provide written informed consent. Participation is voluntary and withdrawal is permitted at any time without consequence to medical care.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- A prospective, randomized, parallel-group trial comparing two uterine closure techniques during primary cesarean section. Participants were randomized in a 1:1 ratio to receive either single-layer hysterorrhaphy (HPU) or double-layer hysterorrhaphy (HDP). Blinding was maintained for the ultrasound evaluators. Uterine scar quality (RMT and niche prevalence) and clinical symptoms are assessed at 6 weeks and 6 months post-surgery.
| Arm | Type | Receives |
|---|---|---|
| Single-layer Uterine Closure (HPU) | Active comparator | Procedure: Single-layer hysterorrhaphy at primary cesarean sectionParticipants allocated to this arm undergo primary cesarean section with single-layer uterine closure (hysterorrhaphy). After fetal and placental extraction, the uterine incision is closed in one single layer using a continuous absorbable suture (polyglactin 910 or equivalent), which approximates the myometrium in a running unlocked pattern. No second imbricating layer is performed. Additional interrupted sutures (reinforcement stitches) may be placed if necessary for bleeding control. All participants are followed postoperatively with standardized transvaginal ultrasound assessments at 6 weeks and 6 months to evaluate residual myometrial thickness (RMT) and cesarean scar defect (niche) development, as well as clinical symptom monitoring. |
| Double-layer Uterine Closure (HDP) | Experimental | Procedure: Double-layer hysterorrhaphy at primary cesarean sectionarticipants allocated to this arm undergo primary cesarean section with double-layer uterine closure (hysterorrhaphy). After fetal and placental extraction, the uterine incision is closed in two distinct layers using a continuous absorbable suture (polyglactin 910 or equivalent). The first layer approximates the myometrium with a running unlocked suture. The second layer invaginates the first using a continuous suture to reinforce the closure and improve hemostasis. Additional interrupted sutures (reinforcement stitches) may be placed if necessary for bleeding control. All participants are followed postoperatively with standardized transvaginal ultrasound assessments at 6 weeks and 6 months to evaluate residual myometrial thickness (RMT) and cesarean scar defect (niche) development, as well as clinical symptom monitoring. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Women aged 18 years or older
- Singleton pregnancy
- Gestational age ≥ 37 weeks (term pregnancy)
- Scheduled or emergency primary cesarean section (first cesarean delivery, no previous uterine scar)
- Low transverse uterine incision (Pfannenstiel or Joel-Cohen approach)
Key exclusion criteria (13 listed)
- Previous uterine surgery (prior cesarean section, myomectomy, uterine perforation, or any procedure leaving a uterine scar)
- Multiple pregnancy (twins or higher-order multiples)
- Preterm delivery (gestational age < 37 weeks)
- Classical (vertical) or inverted T uterine incision
- Placenta previa or placenta accreta spectrum disorder
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Double-layer hysterorrhaphy at primary cesarean sectionAlso: Two-layer uterine closure, Double-layer uterine closure, HDP techniqueAfter fetal and placental delivery, the uterine incision is closed in two layers using continuous absorbable suture (polyglactin 910). Layer 1: running suture approximating the full myometrial thickness. Layer 2: continuous imbricating suture reinforcing the first layer and improving hemostasis. Additional reinforcement sutures placed if needed. Aims to optimize uterine scar healing and reduce cesarean scar defect (niche) formation. | Procedure or surgery | Double-layer Uterine Closure (HDP) |
| Single-layer hysterorrhaphy at primary cesarean sectionAlso: One-layer uterine closure, Single-layer uterine closure, HPU techniqueAfter fetal and placental delivery, the uterine incision is closed in one single layer using a continuous absorbable suture (polyglactin 910) approximating the full myometrial thickness in a running pattern. No second reinforcement layer is performed. Additional reinforcement sutures are placed if needed. This represents the conventional standard technique for uterine closure at cesarean section. | Procedure or surgery | Single-layer Uterine Closure (HPU) |
Primary outcome
Residual Myometrial Thickness (RMT) at the Cesarean Scar at 6 Weeks and 6 Months
Time frame: 6 weeks and 6 months after cesarean section
Residual myometrial thickness (RMT) measured in millimeters at the thinnest point of the uterine scar using standardized transvaginal two-dimensional ultrasound, performed by blinded sonographers according to the protocol of Naji et al. (2012). RMT compared between single-layer (HPU) and double-layer (HDP) closure groups at 6 weeks and 6 months postoperatively.
Prevalence of Cesarean Scar Defect (Niche) at 6 Weeks and 6 Months Postoperatively
Time frame: 6 weeks and 6 months after cesarean section
Cesarean scar defect (niche) defined as a hypoechoic triangular indentation at the site of the uterine incision with depth ≥ 2mm or residual myometrial thickness (RMT)/adjacent myometrial thickness (AMT) ratio < 50%, detected by standardized transvaginal two-dimensional ultrasound. Prevalence compared between single-layer (HPU) and double-layer (HDP) closure groups at 6 weeks and 6 months postoperatively.
9 secondary outcomes
Prevalence of Gynecological Symptoms Related to Cesarean Scar Defect
Time frame: Day 10, 6 weeks, and 6 months after cesarean section
Identification of Independent Risk Factors for Cesarean Scar Defect Formation
Time frame: 6 weeks and 6 months after cesarean section
Cesarean Scar Defect Linear Dimensions
Time frame: 6 weeks and 6 months after cesarean section
Cesarean Scar Defect Volume
Time frame: 6 weeks and 6 months post-cesarean
Operative Duration of Hysterorrhaphy and Total Cesarean Section
Time frame: preoperative (during cesarean section procedure)
Intraoperative Complications Rate
Time frame: Perioperative : During cesarean section procedure
Postoperative Infectious Complications Rate
Time frame: Up to 6 weeks after cesarean section
Hospital Length of Stay
Time frame: Up to 5 days after cesarean section
Blood Transfusion Requirement
Time frame: Up to 5 days after cesarean section
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 May 2026.
- Background: PubMed 23996650Bij de Vaate AJ, van der Voet LF, Naji O, Witmer M, Veersema S, Brolmann HA, Bourne T, Huirne JA. Prevalence, potential risk factors for development and symptoms related to the presence of uterine niches following Cesarean section: systematic review. Ultrasound Obstet Gynecol. 2014 Apr;43(4):372-82. doi: 10.1002/uog.13199.
- Background: PubMed 28070914Di Spiezio Sardo A, Saccone G, McCurdy R, Bujold E, Bifulco G, Berghella V. Risk of Cesarean scar defect following single- vs double-layer uterine closure: systematic review and meta-analysis of randomized controlled trials. Ultrasound Obstet Gynecol. 2017 Nov;50(5):578-583. doi: 10.1002/uog.17401. Epub 2017 Oct 9.
- Background: PubMed 24912096Roberge S, Demers S, Berghella V, Chaillet N, Moore L, Bujold E. Impact of single- vs double-layer closure on adverse outcomes and uterine scar defect: a systematic review and metaanalysis. Am J Obstet Gynecol. 2014 Nov;211(5):453-60. doi: 10.1016/j.ajog.2014.06.014. Epub 2014 Jun 6.
- Background: PubMed 34215598Stegwee SI, Ben AJ, El Alili M, van der Voet LF, de Groot CJM, Bosmans JE, Huirne JAF; 2Close study group. Cost-effectiveness of single-layer versus double-layer uterine closure during caesarean section on postmenstrual spotting: economic evaluation alongside a randomised controlled trial. BMJ Open. 2021 Jul 2;11(7):e044340. doi: 10.1136/bmjopen-2020-044340.
- Background: PubMed 29536581Jordans IPM, de Leeuw RA, Stegwee SI, Amso NN, Barri-Soldevila PN, van den Bosch T, Bourne T, Brolmann HAM, Donnez O, Dueholm M, Hehenkamp WJK, Jastrow N, Jurkovic D, Mashiach R, Naji O, Streuli I, Timmerman D, van der Voet LF, Huirne JAF. Sonographic examination of uterine niche in non-pregnant women: a modified Delphi procedure. Ultrasound Obstet Gynecol. 2019 Jan;53(1):107-115. doi: 10.1002/uog.19049.
- Jordan et al. 2019 - European Niche Task Force consensus on sonographic examination of uterine : nicheSonographic examination of uterine niche in non-pregnant women: a modified Delphi procedureLink provided by the sponsor.
- Individual participant dataSharing planned: No. Individual participant data will not be shared publicly due to patient confidentiality requirements and institutional regulations. Aggregate results will be published in peer-reviewed journals.
Related trials for Cesarean Scar Defect (Isthmococele)
Recruiting
Single- vs Double-Layer Cesarean Scar Repair and Myometrial Thickness
Caesarean Section, Cesarean Scar Closure
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Derbel Mohamed, Professor principal investigator
Department of obstetric and gynaecology of Hedi Chaker sfax
Khanfir Fatma, Professor principal investigator
Department of obstetric and gynaecology of Hedi Chaker sfax
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Double-layer hysterorrhaphy at primary cesarean section and Single-layer hysterorrhaphy at primary cesarean section in people with Cesarean Scar Defect (Isthmococele) and Pelvic Pain, run by Hédi Chaker Hospital at 1 site in Tunisia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Tunisia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Residual Myometrial Thickness (RMT) at the Cesarean Scar at 6 Weeks and 6 Months (time frame: 6 weeks and 6 months after cesarean section). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07611331, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 May 2026.