Ramu Perni, MD, MBA: Benefits of a streamlined aneuploidy assay in obstetric care

Ramu Perni, MD, MBA, Medical Director, Prenatal, BillionToOne; board-certified sub-specialist in maternal-fetal medicine; American Board of Obstetrics and Gynecology, discussed the practical clinical advantages of a unified testing platform. For Perni, the primary goal is to educate the broad spectrum of caregivers—including obstetricians, family practitioners, nurse practitioners, midwives, and genetic counselors—on how early aneuploidy screening can simplify future high-risk management.

In February 2026, BillionToOne announced the launch of UNITY’s expanded Red Blood Cell (RBC) Fetal Antigen non-invasive prenatal test (NIPT), in addition to a first-and-only Platelet Fetal Antigen NIPT. The tests are designed to determine fetal antigen status in pregnancies affected by or at risk of hemolytic disease of the fetus and newborn (HDFN) and fetal and neonatal alloimmune thrombocytopenia (FNAIT).

UNITY, the name of BillionToOne’s product line, now includes the fetal antigen and platelet antigen tests as add-ons to the UNITY aneuploidy assay. “We advise using the Unity aneuploidy assay as a first-line product. If antibodies are identified on a routine antibody screen in pregnancy, the clinician can then add on the RBC antigen test,” Perni explained in a previous interview with Contemporary OB/GYN.

A central component of the UNITY platform is its ability to utilize a single maternal blood draw for multiple clinical needs. Perni emphasized the robustness of the aneuploidy assay as a first-line option that can be performed as early as 9 weeks of gestational age. By establishing this baseline early, clinicians can respond to later complications without requiring additional procedures.

“We can just use the single, one tube of blood that was done from the beginning at 9 weeks, with no requirement for any paternal blood testing,” Perni explained. This approach is "extremely streamlining patient care" by cutting down on the logistical hurdles that typically slow down obstetric and maternal-fetal medicine (MFM) practices.

“While doing all of this, giving the vast majority of patients who do the UNITY aneuploidy assay in the first place—even if additional tests are required—that we can reassure them that there's nothing to worry about and that they can have routine obstetrical care,” Perni added. “So I think that is one of the primary messages.”

Reference:

Fitch J. Ramu Perni, MD, MBA, explains UNITY's expanded Red Blood Cell Fetal Antigen noninvasive prenatal test. Contemporary OB/GYN. Published April 6, 2026. Accessed April 21, 2026. https://www.contemporaryobgyn.net/view/ramu-perni-md-mba-explains-unity-s-expanded-red-blood-cell-fetal-antigen-noninvasive-prenatal-test