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RecruitingNCT06829901Updated Mar 4, 2026

The Effect of Uterine Entry In Fetoscopic Laser Photocoagulation for Twin-To-Twin Transfusion Syndrome

An interventional study of Fetoscopic Laser Photocoagulation in Twin to Twin Transfusion, sponsored by Baylor College of Medicine. Recruiting at 1 site in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-04.

Sponsored by Baylor College of Medicine · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
216
Allocation
Randomized
Ages
18 Years and older
Sex
Female
01

Study summary

The purpose of this study is to evaluate whether the entry technique surgeons use to get inside the uterus to perform fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome has an effect on the rates of chorioamniotic membrane separation.

Read the detailed description

Patients who choose to undergo fetoscopic selective laser photocoagulation (SFLP) at Texas Children's Fetal Center will be offered participation in this research study by study investigators. Description of study rationale and design and a focused interview by the study coordinator to afford potential participants a formal opportunity to examine what they have learned about the research study in the course of their evaluation and discuss how they feel about enrolling in the research study. Once the patient is deemed eligible the informed consent process will be reviewed. If patients elect to participate in the study, informed consent will be obtained, and participants will be provided a copy of the signed consent.

After consent has been obtained, participants will be randomized into two groups ("direct entry" and "Seldinger technique").

Procedure: Selective laser photocoagulation (SFLP) is standard of care for the treatment of complicated monochorionic twin pregnancies. Entry into the uterus for SFLP is achieved under ultrasound guidance using one of two accepted methods, direct entry or the Seldinger technique. Intravenous sedation with local anesthesia at the site of insertion has been found to provide sufficient maternal anesthesia for the procedure.

Group I - Direct entry: The surgeon will gain access to the uterus by inserting a sharp trocar through a small incision in the skin. After access has been established, the trocar is removed and a small tube called a cannula is left in place.

Group II - Seldinger technique: The surgeon will gain access to the uterus by inserting needle through a small incision in the skin and run a guide wire through the needle so a thin tube called a cannula can be placed over the wire.

Follow-Up:

Participants will be monitored after the procedure and upon discharge from the hospital they are free to resume care with their primary doctor. Investigators will collect follow-up data on the health of the participant and the babies until the babies turn one month old.

02

Conditions studied

  • Twin to Twin Transfusion

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Keywords

  • fetoscopic laser photocoagulation
  • TTTS
  • uterine entry
  • direct entry
  • Seldinger technique
  • chorioamniotic membrane separation
  • CAS
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
No

Inclusion criteria

  • Patients who are eligible and elect to undergo fetoscopic selective laser photocoagulation for complicated monochorionic-diamniotic twin pregnancies with twin-to-twin transfusion syndrome.
  • Patients will be between 16 0/7 weeks and 26 0/7 weeks gestational age.

Exclusion criteria

Exclusion Criteria:

  • Patients who do not elect to undergo fetoscopic laser photocoagulation for the treatment of complicated monochorionic-diamniotic twin pregnancies with twin-to-twin transfusion syndrome.
  • Triplets and higher order multiple gestations.
  • Patients who are less than 16 0/7 weeks or greater than 26 0/7 weeks gestational age.
  • Patients with a short cervix (less than 1.5 cm).
  • Patients with a known subchorionic hemorrhage.
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
216 participants (estimated)

Study arms

  • Active comparator
    Direct Entry

    Surgeons will access the uterus to perform fetoscopic laser photocoagulation by inserting a sharp trocar through a small incision in the skin. The trocar is then removed and a small tube called a cannula is left in place.

    Procedure: Fetoscopic Laser Photocoagulation

  • Active comparator
    Seldinger Technique

    Surgeons will access the uterus to perform fetoscopic laser photocoagulation by inserting needle through a small incision in the skin and running a guide wire through the needle so a thin tube called a cannula can be placed over the wire.

    Procedure: Fetoscopic Laser Photocoagulation

Interventions

  • ProcedureFetoscopic Laser Photocoagulation

    Patients who choose to undergo fetoscopic selective laser photocoagulation for complicated monochorionic-diamniotic twin pregnancies with twin-to-twin transfusion syndrome will be offered participation in the study. All participants will undergo selective laser photocoagulation and entry into the uterus will be achieved using one of two accepted methods, either direct entry or the Seldinger technique.

05

What researchers measure

Primary outcomes

  1. Rate of Immediate Chorioamniotic Membrane Separation (CAS)

    Number of participants that have chorioamniotic membrane separation within 24 hours of the procedure.

    Time frame: Up to hospital discharge post-procedure (up to 5 days)

Secondary outcomes

  1. Rate of Chorioamniotic Membrane Separation (CAS)

    Number of participants that have chorioamniotic membrane separation outside the first 24 hours hours following the procedure

    Time frame: From the post-surgical period (outside the first 24 hours) until delivery, up to 25 weeks

  2. Gestational Age at Delivery

    Gestational age at the time of delivery

    Time frame: At delivery

  3. Preterm Birth

    Number of participants that deliver at \<37 weeks gestation

    Time frame: At delivery

  4. Procedure to Delivery Interval

    Days between the participant's procedure and when the babies are delivered

    Time frame: At delivery

  5. Placental Abruption

    As measured by presence in medical record

    Time frame: Up to hospital discharge post-procedure (up to 5 days)

  6. Chorioamnionitis

    As measured by presence in medical record

    Time frame: Up to hospital discharge post-procedure (up to 5 days)

  7. Septostomy

    As measured by presence in medical record

    Time frame: Up to hospital discharge post-procedure (up to 5 days)

  8. Preterm Premature Rupture of Membranes (PPROM)

    As measured by presence in medical record

    Time frame: At delivery

06

Study locations

1 of 1 sites recruiting
  • Texas Children's Hospital - Pavilion for Women
    Houston, Texas 77030, United States
    • Michael Belfort, MD, PhD · Contact · belfort@bcm.edu · 832-826-7375
    • Becky Johnson, MS, CCRP · Contact · rj2@bcm.edu · 832-826-7451
    • Ahmed Nassr, MD, PhD · Principal investigator
    • Michael Belfort, MD, PhD · Sub investigator
    • Magdalena Sanz Cortes, MD, PhD · Sub investigator
    • Roopali Donepudi, MD · Sub investigator
    • Jessian Munoz, MD, PhD · Sub investigator
    • Cara Buskmiller, MD · Sub investigator
    • Brian Burnett, MD · Sub investigator
    Recruiting
07

References and documents

Publications

  • Burnett BA, Munoz JL, Johnson RM, Parobek CM, Delgadillo Chabolla LE, Buskmiller C, Donepudi RV, Sanz Cortes M, Belfort MA, Nassr AA. The effect of uterine entry technique on chorioamniotic membrane separation in fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome: protocol for a randomized controlled trial. BMC Pregnancy Childbirth. 2025 Nov 21;25(1):1253. doi: 10.1186/s12884-025-08410-5. PubMed 41272584 ↗
08

Registry details

Key details

Study ID
NCT06829901
Lead sponsor
Baylor College of Medicine
Responsible party
Ahmed Nassr (Associate Professor, Baylor College of Medicine) — Principal investigator
First posted
Feb 17, 2025
Start date
Mar 14, 2025
Primary completion
Dec 2029 (estimated)
Completion
Dec 2030 (estimated)
Last update
Mar 4, 2026

Study contacts

Ahmed Nassr, MD, PhD
Contact
ahmed.nassr@bcm.edu
832-826-7449
Becky Johnson, MS, CCRP
Contact
rj2@bcm.edu
832-826-7451
Ahmed Nassr, MD, PhD
principal investigator · Baylor College of Medicine

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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