According to a press release published by molecular diagnostics company BillionToOne, over 80,000 individuals have undergone testing for Rhesus (Rh) incompatibility, which can be associated with a variety of conditions, including hemolytic disease of the fetus and newborn (HDFN). This has occurfed despite the recent shortage of RhoGAM— the most common brand of anti-D immune globulin—across the U.S.
Rh incompatibility is known to develop when a pregnant patient has Rh-negative blood and her baby has Rh-positive blood. In fact, in rare circumstances, Rh incompatibility can be associated with a serious condition in which a pregnant person’s immune system attack the baby’s red blood cells, recognizing them as being foreign.
The current protocol for the management of potential Rh incompatibility among the approximately 15% of pregnant individuals who are Rh-negative is prophylactic administration of anti-D immune globulin, which has proven to be extremely effective, having dramatically improved maternal and fetal care in the prior century.
Based on a recent report from the U.S. Food and Drug Administration (FDA), shortages of Kedrion Biopharma’s RhoGAM— the most common brand of anti-D immune globulin—are being reported throughout the United States. Although this treatment is needed to prevent the development of complications, it actually is only necessary if the newborn’s blood is Rh-positive. Thus, treatment with anti-D immune globulin is not required in 40% of the pregnancies—that is, those in which the baby’s blood type is Rh-negative.
Read more about HDFN symptoms and risks
According to Jennifer Hoskovec, MS, Certified Genetic Counselor and Senior Medical Director of Medical Affairs at BillionToOne, “Healthcare providers and blood banks across the U.S. are facing a unique challenge because of the RhoGAM(R) shortage, and it’s important now that the healthcare industry works together to support the treatment of Rh sensitization and its implications.”
She added, “Utilizing cell-free DNA in maternal plasma, an assay known as the UNITY Fetal RhD Non-Invasive Prenatal Test [NIPT], can determine fetal RhD status.”
The UNITY Fetal RhD NIPT provides a reliable, convenient alternative to the use of such traditional techniques for establishing fetal RhD status as paternal testing and the more invasive amniocentesis procedure, according to the company. When the UNITY Fetal RhD NIPT is applied, the RhD status of the fetus can be correctly established from maternal blood at as early as 10 weeks’ gestational age.
Based on a greater than 99.9% rate of sensitivity and specificity, as well as 100% concordance with newborn outcomes, the diagnostic accuracy of the UNITY Fetal RhD NIPT is excellent. The FDA has approved a separate version of the assay (Clinical Trial Assay [CTA]) for utilization in a phase 3 clinical trial in a global collaboration with Janssen Research & Development, LLC.
