Noninvasive Test Confirms High-Risk Prenatal Screening Results from Blood

Noninvasive prenatal screening (NIPT) is widely used to assess fetal chromosomal risk, but a high‑risk result still requires confirmation by chorionic villus sampling or amniocentesis. These invasive procedures carry a small risk of pregnancy loss and can be difficult to access, leaving many patients without timely, definitive answers. A newly launched test now offers noninvasive confirmation of high‑risk screening results by analyzing intact fetal cells from a maternal blood draw.

BillionToOne (Menlo Park, CA, USA) has introduced Unity Confirm, a circulating fetal cell–based confirmation test designed for use following a high‑risk Unity Aneuploidy Screen result. The test is intended for patients who cannot, or choose not to, undergo invasive diagnostic procedures before 16 weeks of gestation. Unity Confirm is available for Trisomy 21, Trisomy 18, Trisomy 13, 22q11.2 microdeletion, and sex chromosome aneuploidies (XXY, XYY, and XXX), and requires Unity Aneuploidy Screen as the front‑line screen.

The assay uses the company’s Fetal Cell Capture technology, a multi‑step immunologic enrichment and single‑cell isolation process that recovers intact circulating fetal cells from maternal blood, effectively providing 100% fetal fraction. Whole‑genome sequencing (WGS) is performed on each isolated cell, enabling direct analysis of fetal trophoblasts rather than fragmentary cell‑free DNA (cfDNA). By targeting fetal cells, the approach aims to deliver chorionic villus sampling (CVS)–like insights from a single blood draw.

In BillionToOne’s clinical validation, Unity Confirm showed 100% concordance with known fetal outcomes and invasive diagnostic results across 16 samples, including affected fetuses with common aneuploidies and 22q11.2 microdeletion. Cell‑based prenatal genetics has been studied across multiple independent publications in more than 1,500 patients, consistently demonstrating very high concordance when a fetal cell is captured and sequenced. Supporting data for Unity Confirm will be presented at ACOG 2026 in Washington, D.C.

Beginning on May 28, providers using Unity Aneuploidy Screen will have access to Unity Confirm after a high‑risk result. To further validate performance at scale, enrollment is underway for a prospective study targeting 1,000 patients to measure concordance with invasive diagnostic testing.

“For years, the idea of capturing whole fetal cells non-invasively was largely viewed as an elusive holy grail, something theoretically possible but practically out of reach,” said Oguzhan Atay, Ph.D., Co-founder and CEO of BillionToOne. “Unity Confirm is proof that it does not have to be. For the first time, a clinician can confirm a high-risk prenatal result non-invasively, with a level of accuracy the field has never before seen outside of an invasive procedure. For the first time, this technology is broadly accessible.”

“A high-risk NIPT result does not give you a diagnosis. It gives you a decision to make under enormous stress, often without enough information,” said Haywood Brown, M.D., Chief Medical Officer, Prenatal, BillionToOne. “For too long, the options were limited: forgo confirmation, or undergo an invasive procedure with a small but real risk. What makes Unity Confirm truly different is not just the science; it is that this capability is now clinically accessible. That’s not an incremental improvement. That is a fundamentally different standard of care.”