The UNITY test developed by BillionToOne in collaboration with Johnson & Johnson is a non-invasive prenatal test used to determine whether Rh immunoglobulin is required in pregnant Rh-negative women.
It does this by detecting the fetal antigens in the blood of pregnant women who have produced antibodies against the fetus’ red blood cells. The risk of the fetus developing hemolytic disease of the fetus and newborn (HDFN) is high if these antigens are present. If the fetus doesn’t express the antigens of interest, unnecessary monitoring, healthcare resources and health-related anxiety can be avoided.
What is HDFN?
Hemolytic disease of the fetus and newborn (HDFN) is an immune-mediated red blood cell (RBC) disorder that occurs when a baby’s RBCs break down quickly, which is called hemolysis. HDFN is caused by a mismatch between a mother’s and her baby’s blood type (A, B, AB, or O) or Rhesus (Rh) factor (Rh-positive or Rh-negative) during pregnancy. Numerous antibodies to RBC antigens can be linked to HDFN, such as those from the ABO and Rh blood group systems.
If left undiagnosed and untreated, HDFN can result in severe fetal anemia, which can lead to swelling of the internal organs, cardiac arrest and even fetal death. Early detection of the risk of HDFN is therefore essential for ensuring timely treatment if HDFN symptoms occur in the fetus.
Learn more about HDFN testing and diagnosis
What antigens does UNITY test for?
The UNITY Fetal Antigen Noninvasive Prenatal Test (NIPT) is a next-generation sequencing (NGS) test which can accurately identify pregnant women at high risk for developing HDFN, from as early as 10 weeks. It is a simple and almost 100% accurate prenatal test that will dramatically improve the identification of women at the highest risk of HDFN.
The UNITY test can detect the following antigens: RhD, RhC, Rhc, RhE, Kell (K) and Fya.
Other conditions the UNITY test screens for
In addition to its role in HDFN risk assessment, the UNITY Complete prenatal test provides several other genetic insights about a developing baby. It can identify changes to the baby’s genes and chromosomes.
This analysis is based purely on the mother’s blood, with no need to take a sample from the father. One sample of the mother’s blood will be screened for the following conditions:
- Sickle cell disease
- Cystic fibrosis
- Alpha thalassemia
- Spinal muscular atrophy
- Beta thalassemia
- Down syndrome
- Edwards syndrome
- Patau syndrome
- Jacobs syndrome
- Turner syndrome
- Triple X syndrome
- Klinefelter syndrome
The sex of the baby can also be determined with the test during the first trimester.
What to expect if you schedule the test
The UNITY Complete screening requires a blood test at 10 weeks of pregnancy or later. Results for chromosomal and gender are available after one week, and information about genetic conditions is available after about two weeks.
Accurate and early detection of genetic or chromosomal conditions in the fetus can lead to earlier intervention and treatment, contributing to better outcomes for both mother and baby. For some conditions, such as spinal muscular atrophy, treatment can start shortly after birth, rather than in-utero.
