Verification of Risk Assignment for Whole Chromosome Using SNP-based NIPT in Vanishing Twin Pregnancies

Verification of Risk Assignment for Whole Chromosome Using SNP-based NIPT in Vanishing Twin Pregnancies (VANISH)

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT05004337

Acronym

VANISH

Enrollment

136

Registered

2021-08-13

Start date

2021-07-22

Completion date

2023-11-29

Last updated

2026-08-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Trisomy 13, Trisomy 18, Trisomy 21, Vanishing Twin

Brief summary

The purpose of this study is to collect blood samples from women carrying a vanishing twin pregnancy to further develop Natera's non-invasive prenatal screening test to provide information about possible chromosomal conditions for the living twin

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

FEMALE

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Women with either ultrasound-documented dizygotic (DZ) twin pregnancy or those whose Panorama Test™ results suggest increased risk for vanishing twin

Exclusion criteria

* Monozygotic twin pregnancy * Non twin pregnancy * Maternal history of bone marrow or organ transplantation

Design outcomes

Primary

Measure	Time frame	Description
Develop a new algorithm and methodology that will measure fetal fraction and distinguish between the DT (demised/non-viable twin) and living twin (LT) in dizygotic twins (DZ) with a single LT.	2 years	A new algorithm will be written to analyze the serial research blood samples to return a fetal fraction of each twin, and identify which twin is the DT verses the LT. The fetal fraction measurement will be a percentage, and it will be measurable, or not measurable for each sample.
The accuracy of the new algorithm to determine which of the signals in the Panorama samples correspond to the LT versus the DT.	2 Years	Each complete participant in the study will have multiple maternal blood samples collected, and a child buccal swab. This outcome will use genetic analysis to reflect for each participant if the algorithm correctly or incorrectly identified the LT versus the DT. Accuracy, defined as the number of VT pairs correctly identified as the LT and DT, divided by the total number of VT pairs, will be calculated.

Secondary

Measure	Time frame	Description
The accuracy of the updated algorithm for the assignment of risk for trisomy 21/18/13 for the LT in DZ twins with a single LT.	3 Years	If a sufficient number of trisomy 21/18/13 cases are observed among any of the cases, assess the accuracy of the updated algorithm to correctly determine whether the LT or DT is aneuploidy. Point estimates and 95% confidence intervals for the specificity for the aneuploidy algorithm.

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORLorraine Dugoff, MD

University of Pennsylvania

Outcome results