FOR IMMEDIATE RELEASE

MESA, Ariz. — July 28, 2026

The Marchand Institute for Minimally Invasive Surgery is pleased to announce the online publication of our latest research, appearing today in the American Journal of Obstetrics & Gynecology MFM (AJOG MFM). Our new paper, titled “Single- versus Double-Layer Uterine Closure and Cesarean Scar Outcomes at Defined Postpartum Intervals: A Time-Stratified Meta-Analysis of Randomized Trials,” takes a fresh, time-based look at one of the most debated questions in cesarean technique.

With cesarean delivery among the most common surgical procedures performed worldwide, the way the uterus is closed has real, long-term implications for cesarean scar healing and future pregnancies. This study was designed to clarify how single-layer and double-layer closure compare when outcomes are measured at consistent points in time after delivery.

Read the Full Study Here:

PubMed (NCBI): PMID: 42508570

Official Journal Link (Elsevier): DOI: 10.1016/j.ajogmf.2026.102073

Why Uterine Closure Technique Matters

After a cesarean delivery, the uterine incision can heal in ways that leave behind a “niche” — a defect in the scar that has been linked to abnormal bleeding, pain, and complications in subsequent pregnancies. Two techniques dominate practice: closing the uterine wall in a single layer or in two layers. Prior studies have offered conflicting conclusions, in part because they measured healing at different, inconsistent times after surgery.

Study Design and Methodology

Our team conducted a systematic review and time-stratified meta-analysis of randomized controlled trials, following PRISMA guidelines. We searched PubMed, Cochrane CENTRAL, Scopus, and Web of Science from inception through November 10, 2025. Two reviewers independently screened records, extracted data, and assessed risk of bias using Cochrane RoB 2, with results pooled using random-effects models and stratified by follow-up interval (6 weeks, 3 months, 6 months, and 12 months) so that each technique was compared at the same point in time.

In total, 21 randomized controlled trials representing 8,564 women met our eligibility criteria after a trustworthiness assessment.

Key Findings

• Uterine rupture or dehiscence: The primary outcome did not differ significantly between the two techniques (risk ratio 1.97, 95% CI 0.66–5.94).
• Niche incidence: No significant difference was found between single- and double-layer closure at any time point.
• Residual myometrial thickness: Double-layer closure was associated with a thicker residual myometrium at 6 weeks (mean difference -1.07 mm) and at 6 months (mean difference -1.16 mm).
• Niche depth: Single-layer closure was associated with a shallower niche depth at 3 months (mean difference -1.29 mm).

Clinical Takeaways

The findings suggest that while double-layer uterine closure yields greater residual myometrial thickness, it does not appear to reduce niche incidence or the risk of uterine dehiscence compared with single-layer closure. In other words, the improved sonographic markers seen with double-layer closure did not translate into a clear difference in the outcomes that matter most for future pregnancies.

“By aligning our comparisons to the same follow-up intervals, we were able to separate genuine differences in healing from differences that were simply an artifact of when measurements were taken,” said Greg J. Marchand, MD, FACS, FACOG, FICS, Director of the Marchand Institute for Minimally Invasive Surgery. “The clinical significance of these sonographic markers remains uncertain, which is exactly why future trials should focus on long-term clinical outcomes.”

Acknowledgements

We would like to thank our dedicated research staff and contributing authors for their work on this project. This collaborative effort is essential for advancing the field of minimally invasive gynecologic surgery (MIGS) and improving care for women worldwide.

About the Marchand Institute

The Marchand Institute for Minimally Invasive Surgery is a 501(c)(3) tax-exempt non-profit research and educational institution based in Mesa, Arizona (EIN 42-2857240). The Institute produces peer-reviewed systematic reviews and meta-analyses in minimally invasive gynecologic surgery and women’s health, conducts FDA clinical trials, and trains surgeons through an SLS-accredited fellowship. All reviews are prospectively registered with PROSPERO, reported to PRISMA standards and appraised using the Cochrane RoB 2 tool. The Institute accepts no pharmaceutical or medical device industry funding and declares no conflicts of interest. It is directed by Greg J. Marchand, MD, FACS, FACOG, FICS.

For more information on our surgical fellowships or to view our library of research, please visit MarchandInstitute.org.

Media Contact
Maria A. Sainz, Director of Communications and Media Relations
Marchand Institute for Minimally Invasive Surgery
maria@marchandobgyn.com  |  (480) 999-0905

Interview requests, expert commentary topics, boilerplate and high-resolution images: Newsroom & Press Kit. Complete publication record with DOIs and PMIDs: Publications database. Methodology: How we run a review.

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