Despite significant advancements in medicine, the care of pregnant patients with Rh-negative blood type has remained unchanged for 50 years.
Rh factor refers to an inherited protein found on the surface of patients’ red blood cells. A person with the protein has a positive factor status, while someone without — an estimated 15 percent of the population — is Rh-negative. An Rh-negative mother carrying an Rh-positive baby results in a condition called Rh incompatibility, where the mother’s immune system can produce antibodies against fetal red blood cells. If this occurs, these antibodies can affect future pregnancies by destroying the baby’s red blood cells faster than they can be replaced, which sometimes leads to serious complications for the baby, including severe anemia, heart failure or even death during a mother’s second or subsequent pregnancy.
To prevent this from happening, all pregnant patients with Rh negative blood type are given Rho(D) immune globulin (Rhlg) — brand names that include RhoGAM, HyperRHO, Rhophylac and WinRho. RhIG is a sterilized medication made from human blood that, when administered as an injection, stops the mother’s blood from producing antibodies that attack fetal Rh-positive blood cells.
However, 60 percent of Rh-negative patients — those who have babies with Rh-positive blood type — need RhIG. Until recently, there’s never been a reason to question this standard approach — giving almost all Rh-negative patients RhIG. It’s long been accepted as the gold standard of care.
That changed earlier this year when several organizations, including the Food and Drug Administration, announced a nationwide shortage of the most commonly prescribed RhIG, RhoGAM. This, coupled with a growing number of patients cautious about the medications and treatments they receive during pregnancy, has forced healthcare professionals across the country to confront the following question: Should every Rh-negative pregnancy be automatically receiving the medication?
The traditional approach persisted largely because noninvasive tests to determine fetal Rh blood type were not widely available or accessible to pregnant patients in the United States until recently. Cell-free DNA (cfDNA) screening options such as noninvasive prenatal tests done as early as nine weeks, which use a small sample of the mother’s blood to analyze a baby’s DNA for genetic disorders like Down syndrome, can now safely and accurately determine fetal Rh status with that same sample.
Using a cfDNA blood test to assess fetal Rh status is already the standard practice in many countries, including the Britain, Netherlands, Belgium, Denmark, Sweden, and France. It provides information that not only spares many mothers from unneeded RhIG administration — including those who may have a personal hesitation or religious objection to receiving blood-borne products — but can also improve their care experience. Research has demonstrated that a lack of shared decision-making between patients and clinicians can result in “negative consequences for both pregnant persons and their birth partners, such as decisional conflicts, unnecessary costs, complaints, legal consequences and a lack of trust in health care professionals.”
In the United States, using NIPT to assess Rh status would benefit patients, clinicians and health systems — a win-win situation that’s already been supported, in the context of the shortage, by leading professional groups like the American College of Obstetricians and Gynecologists.
NIPT that tests for fetal Rh status improves patient experiences and outcomes by providing families greater involvement in the decision-making of their care. It allows clinicians to conserve RhIG usage for the patients who most need the medication. It reduces costs for health systems and mitigates the risk of future RhIG and RhoGAM shortages.
This medication shortage provides us with a clear opportunity to fundamentally shift how we approach and manage Rh-negative pregnancies. Innovative new cfDNA tools allow us to seize this opportunity to create a future of maternal care where every decision is most informed, every patient is most empowered, and every resource is most wisely used to ensure the best outcomes.