Fact Sheet: Rh D Isoimmunization
When a pregnant woman presents for medical care, it is standard to perform various tests and exams for her and her unborn baby’s health, including a physical exam, ultrasound, and a series of lab tests, including bloodwork to determine blood type and Rh status. Determination of Rh D status is critically important, as it may initiate interventions to prevent severe pregnancy complications in future pregnancies.
Rh Factor and RhoGAM:
Rhesus (Rh) D factor refers to a specific protein found on the surface of red blood cells, present in approximately 85% of the U.S. population. If the blood contains the protein, the woman is Rh D positive, and if the blood does not contain the protein the woman is Rh D negative.
Since most of the population is Rh D positive, it is usually assumed that the father of the baby is Rh D positive unless documented to the contrary. Thus, the fetus may have inherited the Rh D protein from his father, although the fetal blood type is not usually known until after birth. If a woman is Rh D negative (15% of the population) and her fetus is Rh D positive, the woman’s body may produce antibodies against the Rh D protein if exposed to the fetus’s red blood cells in her circulation, termed “isoimmunization” or “alloimmunization”. Exposure to the fetus’s red blood cells can occur following trauma, an invasive procedure, pregnancy loss (either natural miscarriage or induced abortion), or childbirth. Fetal blood cells have been documented circulating in the maternal bloodstream as early as six weeks gestation. Interaction of maternal and fetal blood cells may lead to an enhanced maternal immune response directed against and destroying fetal blood cells in future pregnancies if the fetus carries the Rh D factor, called “hemolytic disease of the newborn.”
To prevent the antibody production, it has long been standard to provide an Rh D immune globulin injection (called RhoGAM) which binds the proteins in the fetal blood, preventing the production of these antibodies. RhoGAM is routinely given following unexplained bleeding in pregnancy, after pregnancy loss at any gestational age, after invasive procedures such as amniocentesis, preemptively at the beginning of the third trimester, and after childbirth in Rh D negative women (unless the father or fetus is documented to also be Rh D negative). Since the 1970s, these routine precautions have reduced the rate of Rh D isoimmunization (antibody production against the baby’s red blood cells) in at-risk pregnancies from approximately 13–16% to approximately 0.14–0.2%.
Recent Changes Recommended by Abortion Advocates:
Unfortunately, that has changed recently, as abortion ideologues have begun advocating for a lower standard of care for women seeking abortion. As recently as 2017, the American College of Obstetricians and Gynecologists (ACOG) stated that “Rh D immune globulin should be given to Rh D-negative women who have a pregnancy termination, either medical or surgical.” They documented that “Rh testing is standard of care in the United States, and Rh D immunoglobulin should be administered if indicated.” In their 2020 updated medical abortion recommendations, ACOG continued to recommend Rh testing and Rh D immunoglobulin when indicated, but then inexplicably stated, “In situations where [testing and RhoGAM] are not available or would significantly delay medication abortion, shared decision making is recommended,” apparently prioritizing immediate access to abortion over the risk of future pregnancy complications. Thus, this pro-abortion medical organization opened the door to omitting this critical intervention, to the detriment of the health of women and their future children. Likewise, the National Abortion Federation released guidelines recommending Rh testing and Rhogam provision only for surgical abortions after eight weeks gestation and chemical abortions after 10 weeks gestation. The Society for Family Planning took its abortion advocacy a step further, publishing recommendations for Rh testing and Rhogam provision only for pregnancies terminated after 12 weeks gestation.
The U.S. Food and Drug Administration (FDA) has a long history of relaxing medical abortion regulations for political and population control reasons, based on biased, inaccurate studies published by the abortion industry. Mifepristone (the first component of the two-pill regimen, along with misoprostol), was first approved through seven weeks gestation under President Clinton in 2000. Its use was then expanded to 10 weeks gestation, with the FDA no longer requiring complication reporting unless a woman died, under President Obama in 2016. Egregiously, in 2021 under President Biden, in-person requirements were permanently removed by the FDA, allowing chemical abortion provision by telemedicine, online ordering and mail delivery without physical examination, ultrasound or labs, including crucial Rh testing and RhoGAM provision as documented above. Recently, in early 2023, pharmacy distribution has been allowed. All of these actions will increase the likelihood that a woman will not receive needed Rh testing and RhoGAM.
Dangers of Ignoring the Standard Evidence-Based Rh Testing and RhoGAM Recommendations:
If the standard evidence-based recommendations for Rh testing and RhoGAM provision are ignored and Rh D isoimmunization occurs, the consequences for future children may be severe. Although the U.S. has heretofore consistently followed these recommendations so that Rh D isoimmunization is rare, other countries have not been so fortunate. In countries without consistent Rh testing and RhoGAM provision, if a woman becomes isoimmunized and does not receive invasive in-utero treatment during her pregnancy, 14% of the fetuses are stillborn and one half of live-born infants suffer neonatal death or brain injury. Such a future may lie ahead for American women and their children due to the irresponsible promotion of unsupervised chemical abortion by ideologues, and the complicity of governmental agencies like the FDA, who have been tasked with protecting Americans from dangerous drugs, but have instead prioritized pro-abortion ideology. The time to avert this tragedy is now.
 Rh Factor. Cleveland Clinic. Available at https://my.clevelandclinic.org/health/diseases/21053-rh-factor, accessed January 11, 2023.
 Fiala C, Fux M. Rh-prophylaxis in early abortion. Acta Obstet Gynecol Scand 2003;82(10): 892-903.
 The life-saving science behind RhoGAM. Kedrion Biopharma. Available at https://www.rhogam.com/rhogam-science/, accessed January 11, 2023.
 de Haas M, Finning K, Massey E, Roberts DJ. Anti-D prophylaxis: past, present and future. Transfus Med 2014;24:1–7; Bowman J. Thirty-five years of Rh prophylaxis. Transfusion 2003;43:1661–6.
 American College of Obstetricians and Gynecologists. (2017). Practice Bulletin 181: Prevention of Rh D Alloimmunization. Obstetrics & Gynecology 130(2),481-483.
 American College of Obstetricians and Gynecologists. (2014). Practice Bulletin 143: Medical management of first-trimester abortion. Obstetrics & Gynecology 123(3):667–92.
 American College of Obstetricians and Gynecologists. (2020). Practice Bulletin 225: Medical management of first trimester abortion. Obstetrics & Gynecology. 2020;136(4):855-858.
 Mark A, Foster A, Grossman D. Foregoing Rh testing and anti-D immunoglobulin for women presenting for early abortion: a recommendation from the National Abortion Federation’s Clinical Policies Committee. Contraception. 2019;99:265-266.
 Horvath S, Goyal V, Traxler S, Prager S. Society of Family Planning committee consensus on Rh testing in early pregnancy. Contraception. 2022;114:1-5.
 Weddington JR. Letter to President-To-Be Clinton, Jan 6 1992. In: Rasco C, editor. OA/Box OA7455, File Folder: RU-486 [Internet]. Clinton Library; 1992. p. 54–8. Available from https://clinton.presidentiallibraries.us/files/original/f8977047aefa0c1f90a24665cabf95bc.pdf; See also Reardon D, Harrison D, Skop I, Studnicki J, “Preferential Political Treatment and the Waiver of Randomized Trials” in Overlooked Dangers of Mifepristone, the FDA’s Reduced REMS, and Self-Managed Abortion Policies: Unwanted Abortions, Unnecessary Abortions, Unsafe Abortions. (2021). Charlotte Lozier Institute American Reports Series 20. Available at https://lozierinstitute.org/overlooked-dangers-of-mifepristone-the-fdas-reduced-rems-and-self-managed-abortion-policies-unwanted-abortions-unnecessary-abortions-unsafe-abortions/.
 Zipursky A, Paul VK. The global burden of Rh disease. Arch Dis Child Fetal Neonatal Ed 2011;96:F84–5.