Largest Prospective Study in General-Risk Pregnancies Strengthens Evidence for cfDNA Fetal Risk Assessment as a Primary Screen for Recessive Conditions

Rhea-AI Summary

BillionToOne (Nasdaq: BLLN) reported publication in The Green Journal of a large prospective, multi-site study evaluating its Unity Fetal Risk Screen cfDNA test for recessive conditions in a general-risk pregnancy population. The study followed 2,212 pregnant carriers at nine U.S. institutions where partner carrier status was unknown, mirroring routine prenatal practice.

According to BillionToOne, pregnancy outcomes were collected for 98.6% of eligible cfDNA results. Unity Fetal Risk Screen showed 94.4% sensitivity, 99.5% specificity, and >99.9% negative predictive value for cystic fibrosis, spinal muscular atrophy, and alpha- and beta-hemoglobinopathies, and delivered personalized fetal risk estimates ranging from as high as 9-in-10 to as low as 1-in-10,000. The company said performance was consistent across a racially and ethnically diverse population and that the data strengthen the evidence for using cfDNA fetal risk assessment as a primary screen within its Unity Complete prenatal portfolio.

Positive

• 2,212 pregnant carriers enrolled in prospective, multi-site general-risk study
• Outcome data obtained for 98.6% of pregnancies completing care
• Unity Fetal Risk Screen sensitivity reported at 94.4%
• Assay specificity reported at 99.5% with >99.9% NPV
• Personalized fetal risk estimates from 9-in-10 to 1-in-10,000
• Consistent performance across racially and ethnically diverse population

Negative

• None.

Market Context

BLLN's historical news reactions ranged from -38.89% to +7.45%, adding a mixed-response backdrop to ...

Analysis

BLLN's historical news reactions ranged from -38.89% to +7.45%, adding a mixed-response backdrop to this clinical evidence. The platform record also showed Net Selling insider activity, warranting attention alongside screening adoption evidence.

Key Figures

Study population: 2,212 pregnant carriers Outcome ascertainment: 98.6% of pregnancies Sensitivity: 94.4% +5 more

8 metrics

Study population 2,212 pregnant carriers Prospective study across nine U.S. institutions

Outcome ascertainment 98.6% of pregnancies Pregnancies completing care at participating sites

Sensitivity 94.4% Unity Fetal Risk Screen

Specificity 99.5% Unity Fetal Risk Screen

Negative predictive value >99.9% Unity Fetal Risk Screen

Maximum fetal risk 9-in-10 Personalized quantitative fetal risk assessment

Traditional screening risk 1-in-4 Maximum risk when both partners are confirmed carriers

Minimum fetal risk 1 in 10,000 Personalized quantitative fetal risk assessment

Historical Context

5 past events · Latest: Aug 05 (Positive)

Pattern 5 events

Date	Event	Sentiment	24h Move	Catalyst
Aug 05	Earnings report	Positive	-38.9%	Revenue growth, profitability, reiterated guidance, and planned prenatal portfolio expansion
Jul 20	Leadership change	Positive	-4.0%	Oncology chief medical officer appointed to lead Northstar medical strategy
Jul 15	Earnings scheduling	Neutral	+4.0%	Second-quarter financial results and conference call scheduled for August 5
Jun 29	Clinical data	Positive	+1.9%	Northstar Response outperformed imaging in predicting immunotherapy outcomes
May 27	Conference participation	Neutral	+7.5%	Management scheduled to present at William Blair Growth Stock Conference

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Pattern Detected

Positive company news has produced mixed historical reactions, including substantial divergence after the August 5 earnings report.

Key Terms

cfDNA, NIPT, negative predictive value, hemoglobinopathies

4 terms

cfDNA medical

"supporting routine use of cfDNA fetal risk assessment in general-risk pregnancies"

Cell-free DNA (cfDNA) is short fragments of genetic material that float freely in the bloodstream after cells die and release their contents. Investors care because cfDNA can be sampled with a simple blood draw to reveal signs of pregnancy complications, organ damage, or cancer without invasive procedures, making it the basis for high-growth diagnostic tests, monitoring tools and companion products that can change how diseases are detected and treated.

NIPT medical

"This is the first prospective NIPT study conducted in an intended-use screening population"

Non-invasive prenatal testing (NIPT) is a blood test that screens for certain genetic conditions in a fetus by examining small fragments of the baby’s DNA present in the pregnant person’s blood, avoiding invasive procedures that enter the womb. It matters to investors because test uptake, accuracy, regulatory approval, and pricing determine revenue and margins for companies offering the technology—think of NIPT as a safer, earlier health check (like a smoke alarm for genetic risk) that can drive demand and competitive dynamics in healthcare markets.

negative predictive value medical

"the assay demonstrated 99.5% specificity and >99.9% negative predictive value"

Negative predictive value is a measure of how reliable a negative result is in confirming that a person or situation is truly free of a problem or condition. For investors, it indicates the likelihood that a negative signal or indicator truly means there is no risk or issue present, helping them assess how much trust to place in avoiding potential problems based on current information.

hemoglobinopathies medical

"alpha- and beta-hemoglobinopathies, collecting outcomes for 98.6% of pregnancies"

Inherited disorders of hemoglobin, the oxygen-carrying protein in red blood cells, that change hemoglobin’s structure or production and cause anemia, pain crises, organ damage, or other health problems. Think of hemoglobin as the engine in a car: hemoglobinopathies are defects in that engine or how many engines are made, affecting how well the body transports oxygen. They matter to investors because they define patient populations, treatment needs, regulatory pathways, and potential market size for drugs, diagnostics, and therapies.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Study of more than 2,200 pregnant carriers demonstrates strong clinical performance in the intended-use, general-risk population, with outcomes available for more than 98% of eligible cfDNA results

MENLO PARK, Calif., Aug. 18, 2026 /PRNewswire/ -- BillionToOne, Inc. (Nasdaq: BLLN), a next-generation molecular diagnostics company with a mission to create powerful and accurate tests that are accessible to all, today announced publication of A Prospective, Multi-Site Study of Performance of Cell-Free DNA Testing for Recessive Conditions in a Large, General-Risk Pregnancy Population in The Green Journal. This is the first prospective NIPT study conducted in an intended-use screening population with near-complete pregnancy outcome ascertainment, providing important new evidence supporting routine use of cfDNA fetal risk assessment in general-risk pregnancies.

Conducted across nine U.S. institutions, the prospective study evaluated 2,212 pregnant carriers in which partner carrier status was unknown at the time of testing. Unlike studies enriched with known high-risk couples or pregnancies with other indications of increased fetal risk, this design reflects how cfDNA fetal risk assessment is used as a primary screen in routine prenatal care. Investigators assessed these carriers with cfDNA fetal risk results for cystic fibrosis, spinal muscular atrophy, and alpha- and beta-hemoglobinopathies, collecting outcomes for 98.6% of pregnancies completing care at participating sites. 

Traditional carrier screening depends on partner testing to determine fetal risk, but partner follow-up is often incomplete, delayed, or unavailable due to logistical, financial, and access barriers¹. Unity Fetal Risk Screen demonstrated 94.4% sensitivity, confirming that this approach identifies more affected pregnancies than traditional carrier screening alone, which classifies fewer than 50% of affected pregnancies as high-risk, mainly due to incomplete partner screening. This advantage holds even in the ideal scenario in which every partner completes testing: carrier screening detects approximately 90% of spinal muscular atrophy carriers, 95% of alpha-thalassemia cases, and up to 99% of cystic fibrosis carriers, and the tested partner may not always be the biological father. Unity Fetal Risk Screen overcomes both limitations by assessing fetal risk directly rather than inferring it from parental genotypes.

In addition to excellent sensitivity, the assay demonstrated 99.5% specificity and >99.9% negative predictive value. Unity Fetal Risk Screen provides a personalized, quantitative fetal risk as high as 9-in-10 — compared to the maximum 1-in-4 risk offered by traditional screening when both partners are confirmed carriers — and as low as 1 in 10,000, giving patients added reassurance.

"Multi-center studies with this level of outcome completeness are rare in prenatal screening," said Eliza McElwee, MD, Assistant Professor College of Medicine Department Obstetrics Gynecology at Medical University of South Carolina. "These results provide clinicians with a much stronger evidence base for incorporating cfDNA fetal risk assessment into routine carrier screening, with data that are directly relevant to everyday clinical practice."

The study also demonstrated consistent performance across a racially and ethnically diverse population, supporting equitable access to prenatal genetic screening without the need for partner testing. Researchers point to the growing urgency of early detection, as new therapies show that earlier diagnosis can meaningfully change outcomes for affected children.

"This publication shows that carrier screening with cfDNA fetal risk assessment performs reliably in the general-risk population, not just in a research setting," said Haywood Brown, MD, Chief Medical Officer, Prenatal at BillionToOne. "For patients, that means a high-risk pregnancy is far less likely to be missed simply because a partner sample was never collected."

Unity Fetal Risk Screen is part of BillionToOne's Unity Complete^® prenatal screening portfolio, combining carrier screening, cfDNA-based fetal risk assessment, and aneuploidy screening to deliver prenatal genetic information from a single maternal blood draw via the company's proprietary Quantitative Counting Template™ (QCT™) technology. The publication follows BillionToOne's recent announcement that it is expanding its fetal risk screen portfolio to include a new 130-gene panel, reflecting the company's continued investment in advancing comprehensive prenatal screening and fetal risk assessment.

About BillionToOne
Headquartered in Menlo Park, California, BillionToOne is a next-generation molecular diagnostics company with a mission to create powerful and accurate tests that are accessible to all. The company's proprietary single-molecule next-generation sequencing (smNGS) platform is the only multiplex technology that can detect and precisely quantify genetic targets at the physical limit of detection, down to the single DNA molecule. Enabled by Quantitative Counting Templates™ (QCTs™), the platform quantifies disease-related DNA fragments with single base-pair resolution, providing absolute quantification. For more information, visit www.billiontoone.com.

This press release contains certain forward-looking statements within the meaning of federal securities laws. These forward-looking statements generally are identified by the words "believe," "project," "expect," "anticipate," "estimate," "intend," "strategy," "future," "opportunity," "plan," "may," "should," "will," "would," "will be," "will continue," "will likely result," and similar expressions. Forward-looking statements are predictions, projections and other statements about future events that are based on current expectations and assumptions and, as a result, are subject to risks and uncertainties. Forward-looking statements in this press release include, but are not limited to, statements regarding incorporation of cfDNA fetal risk assessment into routine carrier screening. These statements are based on management's current expectations, forecasts and assumptions, and actual outcomes and results could differ materially from these statements due to a number of factors, some of which are beyond BillionToOne's control. These and additional risks and uncertainties could affect BillionToOne's financial and operating results and cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. These risks and uncertainties include, but are not limited to, those discussed under the captions "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operation" and elsewhere in BillionToOne's Annual Report on Form 10-K, BillionToOne's most recently filed Quarterly Report on Form 10-Q, and other filings we make with the Securities and Exchange Commission from time to time. The forward-looking statements in this press release are based on information available to BillionToOne as of the date hereof, and BillionToOne disclaims any obligation to update any forward-looking statements provided to reflect any change in its expectations or any change in events, conditions, or circumstances on which any such statement is based, except as required by law. These forward-looking statements should not be relied upon as representing BillionToOne's views as of any date subsequent to the date of this press release.

Media Contact

billiontoone@moxiegrouppr.com 

¹ Giles Choates M, Stevens BK, Wagner C, Murphy L, Singletary CN, Wittman AT. It takes two: uptake of carrier screening among male reproductive partners. Prenat Diagn. 2020 Feb;40(3):311-316. doi: 10.1002/pd.5588. Epub 2019 Dec 2. PMID: 31793013.

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SOURCE BillionToOne

FAQ

What did BillionToOne (NASDAQ: BLLN) announce on August 18, 2026 about its Unity Fetal Risk Screen?

BillionToOne announced publication of a large prospective study of its Unity Fetal Risk Screen. According to BillionToOne, the multi-site trial in general-risk pregnancies supports using cfDNA fetal risk assessment as a primary screen for recessive conditions within routine prenatal care.

How large was the BillionToOne Unity Fetal Risk Screen study in general-risk pregnancies (BLLN)?

The study evaluated 2,212 pregnant carriers at nine U.S. institutions. According to BillionToOne, outcomes were available for 98.6% of pregnancies completing care, providing near-complete pregnancy outcome ascertainment in an intended-use, general-risk screening population.

What clinical performance did the Unity Fetal Risk Screen demonstrate for BLLN in this study?

Unity Fetal Risk Screen showed 94.4% sensitivity, 99.5% specificity, and >99.9% negative predictive value. According to BillionToOne, these metrics were observed for cystic fibrosis, spinal muscular atrophy, and alpha- and beta-hemoglobinopathies in a general-risk pregnancy population.

How does BillionToOne’s Unity Fetal Risk Screen compare with traditional carrier screening for BLLN investors?

Unity Fetal Risk Screen directly assesses fetal risk rather than inferring it from both parents. According to BillionToOne, it identified more affected pregnancies than traditional carrier screening alone, which often misses cases because partner testing is incomplete, delayed, or unavailable.

What fetal risk range can Unity Fetal Risk Screen report in BillionToOne’s study?

Unity Fetal Risk Screen can provide personalized fetal risk as high as 9-in-10 and as low as 1-in-10,000. According to BillionToOne, this quantitative range offers more granular information than traditional screening’s maximum 1-in-4 risk when both partners are carriers.

Did BillionToOne report performance of Unity Fetal Risk Screen across diverse populations (BLLN)?

Yes, the study showed consistent performance across a racially and ethnically diverse population. According to BillionToOne, this supports equitable access to prenatal genetic screening without requiring partner testing, aligning with the company’s goal of broad accessibility.

How does Unity Fetal Risk Screen fit into BillionToOne’s Unity Complete prenatal portfolio (NASDAQ: BLLN)?

Unity Fetal Risk Screen is a component of the Unity Complete prenatal screening portfolio. According to BillionToOne, Unity Complete combines carrier screening, cfDNA-based fetal risk assessment, and aneuploidy screening using its Quantitative Counting Template technology from a single maternal blood draw.