CClinicalTrials.gg
RecruitingNCT02621645TRAPISTUpdated Jul 10, 2024

TRAP Intervention STudy: Early Versus Late Intervention for Twin Reversed Arterial Perfusion Sequence

A Phase 4 interventional study of Early selective reduction of TRAP mass and Late selective reduction of TRAP mass in Twin Reversal Arterial Perfusion Syndrome, sponsored by Universitaire Ziekenhuizen KU Leuven. Recruiting at 14 sites in 11 countries. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2024-07-10.

Sponsored by Universitaire Ziekenhuizen KU Leuven · Phase 4, Interventional, and Treatment

From the registry’s dates

  • Primary completion was expected by Jun 2025, 1 year 4 months ago, but the record still lists the study as recruiting.
  • Started May 2016; still recruiting 10 years 5 months later.
Phase
Phase 4
Study type
Interventional
Enrollment
126
Allocation
Randomized
Ages
18 Years and older
Sex
Female
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Study summary

Multi-center open-label randomized controlled trial to assess if early intervention (12.0-14.0 weeks) (study group) improves the outcome of TRAP sequence as compared to late intervention (16.0-19.0 weeks) (control group). The investigators will randomly assign women diagnosed with TRAP sequence diagnosed between 12.0 and 13.6 weeks to an early or late intervention group (1:1), using a web-based application and a computer-generated list with random permuted blocks of sizes 2 or 4 (www.sealedenvelope.com), stratified by gestational age (GA) at inclusion (11.6 -12.6 weeks versus 13.0-13.6 weeks). Analysis will be by intention to treat.

Read the detailed description

The investigators propose to conduct a multi-center open-label randomized controlled trial to assess if early intervention (12.0-14.0 weeks) (study group) improves the outcome of TRAP sequence as compared to late intervention (16.0-19.0 weeks) (control group). The investigators will randomly assign women diagnosed with TRAP sequence diagnosed between 11.6 and 13.6 weeks (1:1) to an early or late intervention group, using a web-based application (www.sealedenvelope.com) with a computer-generated list with random permuted blocks of sizes 2 or 4, stratified by gestational age at inclusion (11.6 -12.6 weeks versus 13.0-13.6 weeks). Analysis will be by intention-to-treat. Outcome will be adjudicated blinded to group allocation.

All interventions will be done under local anaesthesia and/or conscious sedation in sterile conditions by an experienced operator. They must be performed within 1 week after randomisation and at the latest at 14.0 weeks in the early group and 19.0 weeks in the late group. In the early group, only intrafetal coagulation will be used. Intrafetal ablation will be performed under ultrasound guidance using an 18-gauge (1.27 mm) to 20-gauge (0.91 mm) needle with a free-hand technique. The needle is introduced into the pelvis/abdomen of the TRAP mass close to the intra-abdominal portion of the feeding vessel, while avoiding puncture of the placenta and pump twin sac. The procedure is considered successful when there is complete cessation of reverse flow into the TRAP mass on intraoperative color-flow mapping.

In the late intervention/control group either intrafetal coagulation or fetoscopic laser coagulation will be performed of the cord and/or anastomosing vessels, unless the flow has stopped spontaneously or demise of the pump twin has occurred in the meantime. Intrafetal coagulation is done as described above by using a 17-gauge (1.47 mm) to 20-gauge needle. Alternatively, fetoscopic laser coagulation of the cord or anastomosing vessels can be performed through a 17-gauge to 7 French trocar with 1-1,3 mm fetoscope and 400 μm laser fiber. The rationale not to standardize the technique in the late intervention group is that several techniques have been reported for treatment after 16 weeks without any significant differences in outcome. Also, it is usual for the surgeon to adapt the technique to the requirements of each individual case, e.g. for a posterior placenta, the surgeon may prefer fetoscopic rather than intrafetal coagulation. Not restricting the technique to only 1 option will therefore more truly represent current practice and increase the generalizability of the trial's findings.

Patients will be discharged the same day or 1 day after the procedure. Management and follow-up will be similar for the study and the control or current practice group. A follow-up scan is usually performed 1 week after the intervention to check for fetal well-being and exclude anemia. A detailed ultrasound scan will be arranged in a fetal medicine center at 20 and 30 weeks to assess the heart and brain anatomy. Some centers may offer an MRI scan at around 30 weeks as part of the protocol for monochorionic twin pregnancies that underwent an intrauterine intervention. Antenatal, peripartum and postnatal care of the mother will be similar to that of a singleton pregnancy and at the discretion of the referring physician. Intrauterine intervention for TRAP sequence is not an indication for cesarean or elective preterm birth.

02

Conditions studied

  • Twin Reversal Arterial Perfusion Syndrome

Keywords

  • monochorionic
  • TRAP
  • acardiac twin
03

In context

Lead sponsor

Universitaire Ziekenhuizen KU Leuven is the lead sponsor of 928 studies on the registry; 261 are open to participants now.

Of its 5 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

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

Inclusion criteria

  • TRAP sequence in a monochorionic diamniotic twin pregnancy diagnosed between 11.6 and 13.6 weeks, as determined by the crown-rump length of the pump twin in spontaneous conceptions and by the date of insemination or embryonic age at replacement in pregnancies resulting from subfertility treatment
  • Women aged 18 years or more, who are able to consent
  • Anatomically normal pump twin
  • Provide written informed consent to participate in this randomized controlled trial, forms being approved by the Ethical Committees

Exclusion criteria

Exclusion Criteria:

  • Contraindication for an intervention due to a severe maternal medical condition or threatening miscarriage
  • Inaccessibility of the acardiac twin due to a retroverted uterus, severe maternal obesity, uterine fibroids, bowel or placental superposition
  • A major anomaly in the pump twin, requiring surgery or leading to infant death or severe handicap
  • Spontaneous arrest of the reverse flow and/or pump twin demise at diagnosis
05

Study design

Phase
Phase 4
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
126 participants (estimated)

Study arms

  • Experimental
    Early intervention

    Intervention between 12.0 and 14.0 weeks. Early selective reduction of TRAP mass.

    Procedure: Early selective reduction of TRAP mass · Device: Ultrasound-guided intrafetal ablation using a 18 to 20 Gauge needle

  • Active comparator
    Late intervention

    Intervention between 16.0 and 19.0 weeks. Late selective reduction of TRAP mass. This is the standard timing of the intervention. One of two possible techniques for late reduction is chosen by the treating physician.

    Procedure: Late selective reduction of TRAP mass · Device: Ultrasound-guided intrafetal ablation using a 17 to 20 Gauge needle · Device: Laser coagulation of the cord or anastomising vessels through a 17 Gauge to 7 French trocar, with a 1-1,3 mm fetoscope and a 400 µm laser fiber

Interventions

  • ProcedureEarly selective reduction of TRAP mass

    Ultrasound-guided intrafetal ablation using an 18 Gauge to 20 Gauge needle

  • ProcedureLate selective reduction of TRAP mass

    Ultrasound-guided intrafetal ablation using a 17 Gauge to 20 Gauge needle OR fetoscopic laser coagulation of the cord or anastomising vessels through a 17 Gauge to 7 French trocar, with a 1-1,3 mm fetoscope and a 400 µm laser fiber. The treating physician can decide which technique will be used for the selective reduction.

  • DeviceUltrasound-guided intrafetal ablation using a 18 to 20 Gauge needle
  • DeviceUltrasound-guided intrafetal ablation using a 17 to 20 Gauge needle
  • DeviceLaser coagulation of the cord or anastomising vessels through a 17 Gauge to 7 French trocar, with a 1-1,3 mm fetoscope and a 400 µm laser fiber
06

What researchers measure

Primary outcomes

  1. Number of patients with neonatal survival and birth at or after 34.0 weeks of the pump twin

    Time frame: 2 weeks after expected date of birth

Secondary outcomes

  1. Number of patients with need for re-intervention

    This means any kind of fetal intervention, such as repeated intrafetal coagulation, intra-uterine transfusion cord-occlusion...

    Time frame: 2 weeks after expected date of birth

  2. Number of patients with maternal morbidity

    Maternal morbidity is defined as presence of one or more of the following events: * Need for transfusion for hemorrhage * Abruption * Chorioamnionitis as defined on pathology * Sepsis * Bowel perforation * Other serious maternal morbidity requiring admission to ICU

    Time frame: 2 weeks after expected date of birth

  3. Number of patients with miscarriage

    Number of patients with miscarriage before 24 weeks

    Time frame: 2 weeks after expected date of birth

  4. Number of patients with preterm prelabor rupture of membranes (PPROM)

    Number of patients with rupture of membranes before onset of labor and before 37 weeks

    Time frame: 2 weeks after expected date of birth

  5. Number of patients with preterm birth prior to 28 weeks

    Number of patients delivering before 28 weeks

    Time frame: 2 weeks after expected date of birth

  6. Number of patients with preterm birth prior to 32 weeks

    Number of patients delivering before 32 weeks

    Time frame: 2 weeks after expected date of birth

  7. Number of patients with preterm birth prior to 37 weeks

    Number of patients delivering before 37 weeks

    Time frame: 2 weeks after expected date of birth

  8. Time from randomization to delivery

    Number of weeks between randomization and the time of delivery

    Time frame: 2 weeks after expected date of birth

  9. Time from randomization to PPROM

    Number of weeks between randomization and rupture of membranes in patients with PPROM

    Time frame: 2 weeks after expected date of birth

  10. Birth weight in grams

    Time frame: 42 days (28 days neonatal period+2 weeks postdates) after expected date of birth

  11. Number of patients with stillbirth

    Stillbirth refers to all patients with antepartum or intrapartum demise of the fetus

    Time frame: 42 days (28 days neonatal period+2 weeks postdates) after expected date of birth

  12. Number of patients with neonatal death

    Demise of a live-born child within the first 28 days of life

    Time frame: 42 days (28 days neonatal period+2 weeks postdates) after expected date of birth

  13. Number of patients with severe neonatal morbidity

    Severe neonatal morbidity is defined as the presence of at least one of the following: * chronic lung disease (defined as oxygen dependency at 36 weeks gestational age) * patent ductus arteriosus needing medical therapy or surgical closure * necrotizing enterocolitis stage 2 or higher * retinopathy of prematurity stage 3 or higher * ischemic limb injury * amniotic band syndrome * severe cerebral injury (includes at least one of the following: intraventricular hemorrhage grade 3 or higher, cystic periventricular leukomalacia grade 2 or higher, ventricular dilatation greater than the 97th centile, porencephalic or parenchymal cysts or other severe cerebral lesions).

    Time frame: 42 days (28 days neonatal period+2 weeks postdates) after expected date of birth

  14. High volume vs low volume centers of neonatal survival and birth at or after 34.0 weeks of the pump twin and maternal morbidity parameters

    Time frame: 2 weeks after expected date of birth

  15. Number of patients with intact survival rate

    Intact survival rate defined as the number of surviving infants with normal development at two years corrected for prematurity as assessed by the ASQ® score for infant development (Ages \& Stages Questionnaire). A score of more than 2 standard deviations below the mean score for term-born children will be considered abnormal.

    Time frame: 2 years after expected date of birth

  16. Number of patients with normal Bayley III score

    Number of patients with normal Bayley III score at two years of age corrected for prematurity

    Time frame: 2 years after expected date of birth

07

Study locations

14 of 14 sites recruiting
  • Children's Memorial Hermann Hospital
    Houston, Texas, United States
    • Anthony Johnson · Contact
    • Noemi Boring · Contact
    Recruiting
  • Universitätsklinik für Frauenheilkunde und Geburtshilfe
    Graz, Austria
    • Philipp Klaritsch · Contact
    Recruiting
  • Universitaire Ziekenhuizen Leuven
    Leuven, Belgium
    • Liesbeth Lewi · Contact
    Recruiting
  • Mount Sinai Hospital
    Toronto, Canada
    • Tim Van Mieghem · Contact
    • Greg Ryan · Contact
    Recruiting
  • Centre Médico-Chirurgical et Obstétrical
    Schiltigheim, France
    • Romain Favre · Contact
    Recruiting
  • Universitätsklinikum Hamburg-Eppendorf
    Hamburg, Germany
    • Christian Bamberg · Contact
    Recruiting
  • Sheba Medical Center
    Tel Hashomer, Israel
    • Yoav Yinon · Contact
    Recruiting
  • Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico
    Milan, Italy
    • Nicola Persico · Contact
    Recruiting
  • Ospedale dei Bambini Vittore Buzzi
    Milan, Italy
    • Mariano Lanna · Contact
    Recruiting
  • Leiden University Medical Center
    Leiden, Netherlands
    • Dick Oepkes · Contact
    • Monique Haak · Contact
    Recruiting
  • Hospital Universitari Vall d'Hebron
    Barcelona, Spain
    • Carlota Rodo · Contact
    Recruiting
  • Birmingham Women's Hospital
    Birmingham, United Kingdom
    • Mark Kilby · Contact
    Recruiting
  • King's College
    London, United Kingdom
    • Sarah Bower · Contact
    Recruiting
  • St. George's Hospital, University of London (UK sponsor)
    London, United Kingdom
    • Asma Khalil · Contact
    • Sarah Davies · Contact
    Recruiting
08

References and documents

Publications

  • Moore TR, Gale S, Benirschke K. Perinatal outcome of forty-nine pregnancies complicated by acardiac twinning. Am J Obstet Gynecol. 1990 Sep;163(3):907-12. doi: 10.1016/0002-9378(90)91094-s. PubMed 2206078 ↗
  • Pagani G, D'Antonio F, Khalil A, Papageorghiou A, Bhide A, Thilaganathan B. Intrafetal laser treatment for twin reversed arterial perfusion sequence: cohort study and meta-analysis. Ultrasound Obstet Gynecol. 2013 Jul;42(1):6-14. doi: 10.1002/uog.12495. PubMed 23640771 ↗
  • Hecher K, Lewi L, Gratacos E, Huber A, Ville Y, Deprest J. Twin reversed arterial perfusion: fetoscopic laser coagulation of placental anastomoses or the umbilical cord. Ultrasound Obstet Gynecol. 2006 Oct;28(5):688-91. doi: 10.1002/uog.3816. PubMed 16958150 ↗
  • Chaveeva P, Poon LC, Sotiriadis A, Kosinski P, Nicolaides KH. Optimal method and timing of intrauterine intervention in twin reversed arterial perfusion sequence: case study and meta-analysis. Fetal Diagn Ther. 2014;35(4):267-79. doi: 10.1159/000358593. Epub 2014 Apr 16. PubMed 24751835 ↗
  • Lewi L, Valencia C, Gonzalez E, Deprest J, Nicolaides KH. The outcome of twin reversed arterial perfusion sequence diagnosed in the first trimester. Am J Obstet Gynecol. 2010 Sep;203(3):213.e1-4. doi: 10.1016/j.ajog.2010.04.018. Epub 2010 Jun 3. PubMed 20522408 ↗
  • O'Donoghue K, Barigye O, Pasquini L, Chappell L, Wimalasundera RC, Fisk NM. Interstitial laser therapy for fetal reduction in monochorionic multiple pregnancy: loss rate and association with aplasia cutis congenita. Prenat Diagn. 2008 Jun;28(6):535-43. doi: 10.1002/pd.2025. PubMed 18509857 ↗
  • Scheier M, Molina FS. Outcome of twin reversed arterial perfusion sequence following treatment with interstitial laser: a retrospective study. Fetal Diagn Ther. 2012;31(1):35-41. doi: 10.1159/000334156. Epub 2011 Dec 23. PubMed 22204966 ↗
  • Berg C, Holst D, Mallmann MR, Gottschalk I, Gembruch U, Geipel A. Early vs late intervention in twin reversed arterial perfusion sequence. Ultrasound Obstet Gynecol. 2014 Jan;43(1):60-4. doi: 10.1002/uog.12578. PubMed 23908075 ↗
  • Jelin E, Hirose S, Rand L, Curran P, Feldstein V, Guevara-Gallardo S, Jelin A, Gonzales K, Goldstein R, Lee H. Perinatal outcome of conservative management versus fetal intervention for twin reversed arterial perfusion sequence with a small acardiac twin. Fetal Diagn Ther. 2010;27(3):138-41. doi: 10.1159/000295176. Epub 2010 Mar 9. PubMed 20215730 ↗
  • Lewi L, Gratacos E, Ortibus E, Van Schoubroeck D, Carreras E, Higueras T, Perapoch J, Deprest J. Pregnancy and infant outcome of 80 consecutive cord coagulations in complicated monochorionic multiple pregnancies. Am J Obstet Gynecol. 2006 Mar;194(3):782-9. doi: 10.1016/j.ajog.2005.09.013. PubMed 16522413 ↗
  • Kerstjens JM, Nijhuis A, Hulzebos CV, van Imhoff DE, van Wassenaer-Leemhuis AG, van Haastert IC, Lopriore E, Katgert T, Swarte RM, van Lingen RA, Mulder TL, Laarman CR, Steiner K, Dijk PH. The Ages and Stages Questionnaire and Neurodevelopmental Impairment in Two-Year-Old Preterm-Born Children. PLoS One. 2015 Jul 20;10(7):e0133087. doi: 10.1371/journal.pone.0133087. eCollection 2015. PubMed 26193474 ↗
09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 10, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT02621645
Lead sponsor
Universitaire Ziekenhuizen KU Leuven
Collaborators
St. George's Hospital, University of London (UK sponsor), Leiden University Medical Center, Ospedalo Maggiore Policlinico di Milano, Italy, Hospital Universitari Vall d'hebron Barcelona, Spain, Centro Médico-Chirurgical et Obstétrical (CMCO) Schiltigheim, France, Universitätsklinik für Frauenheilkunde und Geburtshilfe Graz, Austria, Ospedale dei Bambini "Vittore Buzzi" Milano, Italy, Birmingham Women's Hospital, UK, Sheba Medical Center, Children's Memorial Hermann Hospital Houston Texas, USA, Universitätsklinikum Hamburg-Eppendorf, Germany, Mount Sinai Hospital, Canada, University of Pittsburgh, University Hospital Innsbruck, Austria, Spedali Civili, University of Brescia, Italy
Responsible party
Sponsor
First posted
Dec 3, 2015
Start date
May 2016
Primary completion
Jun 2025 (estimated)
Completion
Jun 2025 (estimated)
Last update
Jul 10, 2024

Study contacts

Isabel Couck, MD
Contact
isabel.couck@uzleuven.be
+32 16 342294
Liesbeth Lewi, MD PhD
Contact
liesbeth.lewi@uzleuven.be
+32 16 342862
Liesbeth Lewi, MD PhD
study chair · UZ Leuven

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

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