Noninvasive Prenatal Test Diagnoses Hemolytic Disease of Fetus and Newborn

By LabMedica International staff writers
Posted on 05 Oct 2022

Image: Fetal antigen NIPT may help streamline management of most alloimmunized pregnant patients (Photo courtesy of BillionToOne)

Alloimmunization occurs in about 1% of pregnancies and is when the pregnant patient makes RBC antibodies as a result of foreign blood mixing. These antibodies can cross the placenta and attack the unborn baby. Hemolytic Disease of the Fetus and Newborn (HDFN), a rare but potentially deadly resulting condition, can have devastating effects on the fetus including anemia, hyperbilirubinemia, and death. Due to the potential severity of HDFN and the previous lack of non-invasive risk assessment tools, alloimmunized patients are typically monitored closely until delivery, sometimes via weekly blood titers and ultrasounds. This close monitoring determines if an early term delivery or an intrauterine transfusion may be indicated for the pregnancy. Now, a new fetal antigen single-gene non-invasive prenatal test (sgNIPT) for pregnant patients who are alloimmunized with C, c, D, E, Duffy (Fya), or Kell (K) red blood cell (RBC) antibodies looks for the presence of the genetic variants that code for the corresponding fetal antigens.

BillionToOne, Inc. (Palo Alto, CA, USA) has launched UNITY fetal antigen sgNIPT, a new addition to UNITY Screen, that is available at 10+ weeks gestation, and may streamline management for most pregnancies thought to be at risk for HDFN. The UNITY fetal antigen NIPT report will show if the fetal antigen of interest is detected or not detected, providing stronger clinical conviction for those patients who require rigorous monitoring. Importantly, it is expected that up to 65% alloimmunized pregnant patients will not be carrying fetuses that express the antigen(s) of interest. This may drastically minimize unnecessary healthcare resources, decrease monitoring visits, and, most importantly, reduce unnecessary anxiety for many families. Analytical validation data show the test sensitivity and specificity is >99.9%.

"We are thrilled to launch our UNITY fetal antigen sgNIPT. While HDFN only affects 1% of US pregnancies, it can have dire consequences, and the extra, and often unnecessary, monitoring can be a significant source of anxiety for patients," said Oguzhan Atay, BillionToOne CEO. "This is yet another example of our powerful Quantitative Counting Templates (QCT) technology and its application to single-gene NIPT fulfilling a previously unmet medical need. Providing up to 65% of alloimmunized patients with greater peace of mind that their babies are low risk is the type of patient-oriented product we always strive for."

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BillionToOne, Inc.