Bethany and Molly make a mini episode all about cell free fetal DNA, the blood test on mom that can determine a baby’s antigen status beginning around 10 weeks gestation. This is an accurate, non-invasive way to find out if a baby is at risk of HDFN by capturing free-floating fetal DNA from the mother’s blood and testing it to see if baby has the antigen that the mom’s antibodies may attack, causing HDFN. We also suggest listening to Season 1 Episode 2 about Prenatal Blood Tests.
Watch this episode on YouTube
CffDNA is officially recommended in the recently published clinical practice guidelines (listen to previous episode, S4E3, for more information about the guidelines): Moise KJ, Markham KB, Spinella PC, Sherwood MR, Robinson KA, Wilson LM, Malone J, Espinoza J, Dizon-Townson D, Mercer L, Miller R. A Clinical Practice Guideline for the Management of Pregnancy Alloimmunized to Red Blood Cell Antigens. JAMA Network Open. 2025 Nov 3;8(11):e2544649-. Available here. Note that additional practice points are in the supplemental content. To access all recommendations, practice points, and their rationale, we recommend clicking “supplemental content”, downloading the file, and accessing Table 4. This provides all information in one table for easy printing and reference.
Options for cffDNA in various countries:
cffDNA from Sanquin Laboratories (Netherlands; can be shipped internationally) (D, E, C, c, K) Information here.
cffDNA from BillionToOne’s Unity Screen (U.S.) (D, E, C, c, K, Fya) Publication here. Order form here.
cffDNA from Natera’s Panorama test (U.S.) (D) Information here.
cffDNA from NHS (UK/Ireland) (D, E, C, c, K) Information here.
cffDNA from Canadian Blood Services (D, E, C, c, K; 16-20 weeks gestation) Information here.
cffDNA from Lifeblood (Australia) (D, E, K, k, E, c, Fya, Fyb; 12 weeks gestation) Information here.
More resources about cffDNA:
Moise Jr KJ. The use of free DNA for fetal RHD genotyping in the Rh negative pregnant patient—the time has come. American Journal of Obstetrics and Gynecology. 2025 Feb 1;232(2):188-93. Available here.
Gandhi M. Paternal and Fetal Genotyping in the Management of Alloimmunization in Pregnancy. Available here.
Regan F, Veale K, Robinson F, Brennand J, Massey E, Qureshi H, Finning K, Watts T, Lees C, Southgate E, Robinson S. Guideline for the investigation and management of red cell antibodies in pregnancy: A British Society for Haematology guideline. Transfusion Medicine. Available here.
View all of our resources at www.allohopefoundation.org
If you are an alloimmunized mother from any country, you are welcome in our Facebook support group called “Antibodies in Pregnancy: An AHF Support Group. Join here. https://www.facebook.com/groups/antibodiesinpregnancy
Please consider donating to AHF. If you are a listener, you know we do a lot with a little. Not sure how much will make a difference? An antibody screen in Kenya costs $13 USD. A dose of RhIG for a mother who cannot afford it is $80 USD.
to make a one-time or recurring donation.
