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

The Effect of Entry Technique on Chorioamniotic Membrane Separation in Fetoscopic Laser Photocoagulation for Twin-To-Twin Transfusion Syndrome

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.

Study Overview

• Status: Recruiting
• Conditions: Twin to Twin Transfusion
• Intervention / Treatment: Procedure: Fetoscopic Laser Photocoagulation

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.

• Study Type: Interventional
• Enrollment (Estimated): 216
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ahmed Nassr, MD, PhD; Phone Number: 832-826-7449; Email: ahmed.nassr@bcm.edu
• Study Contact Backup: Name: Becky Johnson, MS, CCRP; Phone Number: 832-826-7451; Email: rj2@bcm.edu

Study Locations

• United States
  • Texas
    • Houston, Texas, United States, 77030
      • Recruiting
      • Texas Children's Hospital - Pavilion for Women
      • Sub-Investigator: Roopali Donepudi, MD
      • Sub-Investigator: Magdalena Sanz Cortes, MD, PhD
      • Contact: Becky Johnson, MS, CCRP; Phone Number: 832-826-7451; Email: rj2@bcm.edu
      • Contact: Michael Belfort, MD, PhD; Phone Number: 832-826-7375; Email: belfort@bcm.edu
      • Principal Investigator: Ahmed Nassr, MD, PhD
      • Sub-Investigator: Michael Belfort, MD, PhD
      • Sub-Investigator: Jessian Munoz, MD, PhD
      • Sub-Investigator: Cara Buskmiller, MD
      • Sub-Investigator: Brian Burnett, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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:

• 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.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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; 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.
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; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of Immediate Chorioamniotic Membrane Separation (CAS)	Number of participants that have chorioamniotic membrane separation within 24 hours of the procedure.	Up to hospital discharge post-procedure (up to 5 days)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of Chorioamniotic Membrane Separation (CAS)	Number of participants that have chorioamniotic membrane separation outside the first 24 hours hours following the procedure	From the post-surgical period (outside the first 24 hours) until delivery, up to 25 weeks
Gestational Age at Delivery	Gestational age at the time of delivery	At delivery
Preterm Birth	Number of participants that deliver at <37 weeks gestation	At delivery
Procedure to Delivery Interval	Days between the participant's procedure and when the babies are delivered	At delivery
Placental Abruption	As measured by presence in medical record	Up to hospital discharge post-procedure (up to 5 days)
Chorioamnionitis	As measured by presence in medical record	Up to hospital discharge post-procedure (up to 5 days)
Septostomy	As measured by presence in medical record	Up to hospital discharge post-procedure (up to 5 days)
Preterm Premature Rupture of Membranes (PPROM)	As measured by presence in medical record	At delivery

Collaborators and Investigators

• Sponsor: Baylor College of Medicine
• Investigators: Principal Investigator: Ahmed Nassr, MD, PhD, Baylor College of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): March 14, 2025
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): December 1, 2030

Study Registration Dates

• First Submitted: January 31, 2025
• First Submitted That Met QC Criteria: February 11, 2025
• First Posted (Actual): February 17, 2025

Study Record Updates

• Last Update Posted (Actual): March 4, 2026
• Last Update Submitted That Met QC Criteria: March 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: CAS; Seldinger technique; TTTS; fetoscopic laser photocoagulation; uterine entry; direct entry; chorioamniotic membrane separation
• Additional Relevant MeSH Terms: Infant, Newborn, Diseases; Hematologic Diseases; Anemia; Anemia, Neonatal; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Hemic and Lymphatic Diseases; Fetofetal Transfusion
• Other Study ID Numbers: H-56175

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No