title: Fetal RHD genotyping after bone marrow transplantation.
abstract: Fetal RHD genotyping allows targeted diagnostic testing, fetal surveillance, and eventually intrauterine treatment to D-alloimmunized pregnant women who carry an RHD+ fetus. However, false-positive and false-negative results of noninvasive prenatal fetal RHD genotyping have been described due to a variety of causes. In this case report we present two cases where noninvasive fetal RHD typing was complicated by a previous bone marrow transplantation (BMT).
  
  
  
  We describe two women with a history of allogeneic BMT in early childhood. Both were born D+ and received a transplant of their D- male sibling. Anti-D were detected during pregnancy in one of them. The biologic father of this pregnancy was D+. In both cases polymerase chain reaction procedures specific for RHD on maternal plasma DNA were positive whereas a D- neonate was born in one case (Case 1).
  
  
  
  False-positive results of noninvasive fetal RHD genotyping occur in D+ women transplanted with marrow of a D- donor, due to circulating cell-free DNA originating from nonhematopoietic tissue. The cases highlight that health care professionals and laboratories should be aware that allogeneic BMT can be a cause for false-positive results in fetal RHD genotyping with cell-free DNA in maternal plasma, and likewise the wrong fetal sex can be reported in the case of a male donor and a female fetus. Based on one of the cases we also recommend giving D- blood products to young female patients who receive a BMT of D- donors.
authors.affiliation: Department of Experimental Immunohematology, Amsterdam and Landsteiner Laboratory, Academic Medical Center, Sanquin, University of Amsterdam, Amsterdam, The Netherlands.|Division Woman and Baby, Department of Obstetrics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Florentine F
authors.initials: FF
authors.lastname: Thurik
authors.affiliation: Division Woman and Baby, Department of Obstetrics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Godelieve C M L
authors.initials: GC
authors.lastname: Page-Christiaens
authors.affiliation: Department of Experimental Immunohematology, Amsterdam and Landsteiner Laboratory, Academic Medical Center, Sanquin, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Aicha
authors.initials: A
authors.lastname: Ait Soussan
authors.affiliation: Department of Immunohematology Diagnostic Services, Sanquin, Amsterdam, The Netherlands.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Ligthart
authors.affiliation: Department of Immunohematology Diagnostic Services, Sanquin, Amsterdam, The Netherlands.
authors.forename: Goedele M A F
authors.initials: GM
authors.lastname: Cheroutre
authors.affiliation: Department of Immunohematology Diagnostic Services, Sanquin, Amsterdam, The Netherlands.
authors.forename: Bernadette
authors.initials: B
authors.lastname: Bossers
authors.affiliation: Department of Experimental Immunohematology, Amsterdam and Landsteiner Laboratory, Academic Medical Center, Sanquin, University of Amsterdam, Amsterdam, The Netherlands.|Department of Immunohematology Diagnostic Services, Sanquin, Amsterdam, The Netherlands.
authors.forename: Barbera
authors.initials: B
authors.lastname: Veldhuisen
authors.affiliation: Department of Experimental Immunohematology, Amsterdam and Landsteiner Laboratory, Academic Medical Center, Sanquin, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: C Ellen
authors.initials: CE
authors.lastname: van der Schoot
authors.affiliation: Department of Experimental Immunohematology, Amsterdam and Landsteiner Laboratory, Academic Medical Center, Sanquin, University of Amsterdam, Amsterdam, The Netherlands.|Department of Immunohematology Diagnostic Services, Sanquin, Amsterdam, The Netherlands.|Center for Clinical Transfusion Research, Sanquin Research and Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Masja
authors.initials: M
authors.lastname: de Haas
mesh_terms: D000328:Adult; D016026:Bone Marrow Transplantation; D005260:Female; D005838:Genotype; D006801:Humans; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012204:Rh-Hr Blood-Group System / Q000235:genetics*; D055815:Young Adult
chemical_list: D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen