A physician-facing clinical review of indications, technology, advantages, limitations, and alternatives.
Geographic disparities, procedural risk aversion, and access barriers leave many patients without diagnostic confirmation following a high-risk NIPT result.
T21 · T18 · T13 · Monosomy X · XXX · XXY · XYY
Optional: 22q11.2 microdeletion · Fetal sex
Zygosity for twin pregnancies included.
Up to 14 recessive & X-linked conditions including CF, SMA, sickle cell, α/β-thalassemia, Tay-Sachs, PKU, DMD, Fragile X (optional).
Reflex fetal risk assessment if maternal carrier is positive — no paternal sample required.
Single maternal blood draw · Available from 9–10 weeks gestation · Results: aneuploidies ~1 week · recessive conditions ~2 weeks
Counts fetal DNA molecules down to a single base pair from cfDNA.
Determines fetal genotype in maternal blood — not just parental carrier risk.
~3× increase in detection of affected pregnancies vs. traditional carrier screening.
Proprietary to BillionToOne · Enables single-gene NIPT (sgNIPT) — previously not technically feasible from cfDNA alone.
Effectively 100% fetal fraction for captured cells · Avg. 2.9 fetal cells captured per case · Mean GA at collection: 15w
9 of 16 cases concordant with CVS/amniocentesis. Remaining cases confirmed via postnatal examination or ultrasound findings. Evidence is preliminary; large prospective validation studies are pending.
No risk of procedure-related pregnancy loss (CVS: ~0.5–1%; amniocentesis: ~0.1–0.3%).
Aneuploidies + up to 14 recessive conditions from one maternal blood draw. No paternal sample required.
Addresses geographic and logistical barriers to CVS; provides early confirmatory data for patients who decline invasive testing.
sgNIPT provides individualized fetal risk — not just parental carrier probability. Risk can be stratified to 1:5,000 or 9:10.
Unity Confirm is a screening/confirmatory adjunct — not a replacement for CVS or amniocentesis. Irreversible decisions must not be based on this result alone.
Single-cell analysis may miss mosaic aneuploidy. This limitation is shared with rapid CVS (FISH), but not with cultured karyotype.
Unity Confirm available only through 15w6d. Fetal cell yield decreases with advancing gestational age.
Not available for: monosomy X, twins, vanishing twin, egg donor, gestational surrogacy. Insufficient fetal cell recovery possible.
Laboratory-developed test (CLIA-certified, CAP-accredited). Regulatory status differs from FDA-approved diagnostics.
Preliminary concordance data (n=16). Large, independent validation studies are not yet published.
| Test / Procedure | Type | GA Window | Diagnostic? | Mosaicism | Procedural Risk |
|---|---|---|---|---|---|
| Unity Aneuploidy NIPT | Screening (cfDNA) | ≥9w | ✗ | Limited | None |
| Unity Confirm™ (CFC) | Confirmatory (fetal cell) | 10–15w6d | ✗ | Cannot exclude | None |
| Chorionic Villus Sampling | Diagnostic | 10–14w | ✓ | Rapid CVS limited | ~0.5–1% |
| Amniocentesis | Diagnostic (gold standard) | ≥15–16w | ✓ | Cultured cells | ~0.1–0.3% |
| Expectant Management | Observation / Ultrasound | Any | ✗ | ✗ | None |
Amniocentesis remains the gold standard for diagnostic confirmation of aneuploidy.
High-risk Unity Aneuploidy Screen result (T21, T18, T13, SCAs, 22q11.2)
Singleton gestation ≤15w6d
Patient declines or lacks access to CVS
Seeking additional data prior to amniocentesis decision
High-risk monosomy X result
Twin or higher-order multiple gestations
Vanishing twin pregnancies
Gestational carriers or egg donor pregnancies
Gestational age >15w6d
Unity Confirm is available exclusively following a high-risk Unity Aneuploidy Screen result. Not available as a standalone test.
CVS (10–14w) or amniocentesis (≥15w). Definitive cytogenetic diagnosis. Discuss procedural risk and access.
Non-invasive adjunct. Provides additional genomic data. Does not replace diagnostic testing. Appropriate for informed patients who decline invasive procedures.
Detailed anatomy ultrasound (18–20w). Serial growth surveillance. Neonatal evaluation. Appropriate when patient declines all testing.
Genetic counseling is recommended for all patients with high-risk results. BillionToOne offers complimentary telephone genetic consultation.
First-of-kind test combining aneuploidy NIPT + sgNIPT for recessive conditions from a single draw. Direct fetal risk — no paternal sample needed. ACOG-aligned conditions.
Novel CFC assay providing CVS-like genomic insights non-invasively. Bridges the diagnostic gap for patients declining invasive testing. Preliminary data promising; larger studies needed.
Neither test is diagnostic. Amniocentesis remains the gold standard. Mosaicism cannot be excluded. LDT status — not FDA cleared. Clinical correlation is mandatory.
Addresses a real unmet need in prenatal care. Expands access for underserved populations. Empowers shared decision-making between patients and providers.
| 1. | Son H, et al. Initial clinical outcomes of a circulating fetal cell assay to confirm high-risk aneuploidy cfDNA screening results. BillionToOne White Paper, 2026. |
| 2. | Wynn J, et al. Performance of single-gene NIPT for autosomal recessive conditions. Prenat Diagn. 2023;43(10):1344–1354. |
| 3. | ACOG Committee Opinion No. 691. Carrier screening for genetic conditions. Obstet Gynecol. 2017;129:e41–55. |
| 4. | ACOG Practice Bulletin No. 163. Screening for fetal aneuploidy. Obstet Gynecol. 2016;127(5):e123–e137. |
| 5. | BillionToOne Unity Confirm™ Brochure & Sample Report. unityscreen.com, 2026. |
Unity Confirm is a laboratory-developed test (LDT) performed in a CLIA-certified, CAP-accredited laboratory. It has not been cleared or approved by the FDA. Results should not be used as the sole basis for irreversible clinical decisions. Clinical correlation is mandatory.