BillionToOne's Pioneering Study Demonstrates 100% Accuracy for Non-Invasive Fetal RhD Detection in US Population

Peer reviewed research published in Green Journal shows BillionToOne's NGS technology excels in testing diverse US populations

MENLO PARK, Calif., Feb. 27, 2025 /PRNewswire/ -- BillionToOne, a molecular diagnostics company with a mission to create powerful and accurate tests that are accessible to all, announced today the groundbreaking results from a recent large US-based clinical study demonstrating 100% accuracy in its non-invasive prenatal test (NIPT) for fetal RhD status. This is BillionToOne's third peer reviewed study of its fetal antigen assay, and the second published in The Journal of Obstetrics and Gynecology, the official journal of the American College of Obstetricians and Gynecologists (ACOG), also known as "The Green Journal," which showcases the accuracy and clinical validity of BillionToOne's fetal RhD NIPT.

Approximately 15% of pregnant individuals in the US are RhD-negative. However, in ~40% of these pregnancies, the fetus is also RhD-negative, making RhoGAM administration unnecessary. To date, BillionToOne has conducted RhD testing on 469 participants through clinical validation studies, while providing over 150,000 commercial RhD tests to patients nationwide. 

This study demonstrates that BillionToOne's proprietary next-generation sequencing (NGS) with Quantitative Counting Template™ (QCT™) technology provides conclusive results with 100% accuracy. BillionToOne's study included all samples, including difficult to identify variants such as RHDѰ and RHD-C-DE, which are often excluded in other studies; therefore, it reflected true clinical performance. Across 401 pregnancies, the test achieved 100% sensitivity, specificity, positive predictive value, and negative predictive value when compared to the ground-truth neonatal RhD serology.

"This study provides compelling evidence that our QCT™ technology can revolutionize prenatal care for RhD-negative individuals in the US," said Jennifer Hoskovec, VP of Medical Affairs at BillionToOne. "Our approach accurately determines fetal RhD status even in the presence of complex genetic variants, representing a significant advancement over existing methodologies."

A critical differentiator of BillionToOne's technology is its unique ability to detect challenging RhD variants that other commercial tests typically exclude. The study demonstrated 100% accuracy in identifying fetal RHDѰ variants, found in approximately 25% of Black Rh-negative individuals, and RHD-CE-D hybrid variants. Other commercially available fetal RhD NIPTs are unable to detect the fetal RhD status when these variants are present in the pregnant individual, limiting applicability in a general obstetric population. This capability is particularly crucial for ensuring accurate testing across diverse populations, especially in the US.

The research demonstrates clinical validity, with healthcare providers already implementing the test results to guide RhoGAM administration. The study observed a significant reduction in unnecessary RhoGAM administration for pregnancies with RhD-negative fetuses as clinician confidence in the test grew over time.

This third major fetal antigen publication from BillionToOne follows a recent ACOG clinical practice advisory update supporting the use of non-invasive cell-free DNA screening for fetal RhD during the RhoGAM shortage, and also as an option in alloimmunized pregnancies when amniocentesis is declined. These ACOG updates cited BillionToOne's previous studies.

"By accurately identifying fetal RhD status, we can avoid unnecessary RhoGAM administration in approximately 40% of patients carrying RhD-negative fetuses," said first author of the study, Dr. Julio Mateus Nino, MD, Maternal & Fetal Medicine. "BillionToOne's QCT™ technology also provides critical information for patients with RhD alloimmunization, giving physicians the tools to guide antenatal management based on actual fetal genotype rather than assumption. This is a meaningful advancement in personalized prenatal care that benefits both patients and healthcare systems."

About BillionToOne
Headquartered in Menlo Park, California, BillionToOne is a precision diagnostics company on a mission to make molecular diagnostics more accurate, efficient, and accessible for all. The company's patented Quantitative Counting Template™ (QCT™) molecular counting platform is the only multiplex technology that can accurately count DNA molecules at the single-molecule level as early as 9 weeks gestation. For more information, please visit www.billiontoone.com.

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Mateus-Nino, Julio F. MD; Wynn, Julia MS, MS; Wiggins-Smith, Jenny MD; Bryant, J. Brett MD; Citty, J. Kris MD; Citty, J. Kyle MD; Ahuja, Samir MD; Newman, Roger MD. Clinical Performance of Cell-Free DNA for Fetal RhD Detection in RhD-Negative Pregnant Individuals in the United States. Obstetrics & Gynecology ():10.1097/AOG.0000000000005850, February 27, 2025. | DOI: 10.1097/AOG.0000000000005850

SOURCE BillionToOne