title: Should cell-free DNA testing be used to target antenatal rhesus immune globulin administration?
abstract: OBJECTIVE
  To compare the rates of alloimmunization with the use of cell-free DNA (cfDNA) screening to target antenatal rhesus immune globulin (RhIG) prenatally, versus routine administration of RhIG in rhesus D (RhD)-negative pregnant women in a theoretic cohort using a decision-analytic model.
  
  
  METHODS
  A decision-analytic model compared cfDNA testing to routine antenatal RhIG administration. The primary outcome was maternal sensitization to RhD antigen. Sensitivity and specificity of cfDNA testing were assumed to be 99.8% and 95.3%, respectively. Univariate and bivariate sensitivity analyses, Monte Carlo simulation, and threshold analyses were performed.
  
  
  RESULTS
  In a cohort of 10,000 RhD-negative women, 22.6 sensitizations would occur with utilization of cfDNA, while 20 sensitizations would occur with routine RhIG. Only when the sensitivity of the cfDNA test reached 100%, the rate of sensitization was equal for both cfDNA and RhIG. Otherwise, routine RhIG minimized the rate of sensitization, especially given RhIG is readily available in the United States.
  
  
  CONCLUSIONS
  Adoption of cfDNA testing would result in a 13.0% increase in sensitization among RhD-negative women in a theoretical cohort taking into account the ethnic diversity of the United States' population.
authors.affiliation: a Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology , University of Washington , Seattle , WA , USA .
authors.forename: Kimberly K
authors.initials: KK
authors.lastname: Ma
authors.affiliation: b Department of Obstetrics and Gynecology , Oregon Health & Science University , Portland , OR , USA .
authors.forename: Maria I
authors.initials: MI
authors.lastname: Rodriguez
authors.affiliation: c Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology , University of California , Davis, Sacramento , CA , USA , and.
authors.forename: Yvonne W
authors.initials: YW
authors.lastname: Cheng
authors.affiliation: d Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Medicine , University of California , San Francisco , CA , USA.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Norton
authors.affiliation: b Department of Obstetrics and Gynecology , Oregon Health & Science University , Portland , OR , USA .
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Caughey
mesh_terms: D001788:Blood Grouping and Crossmatching; D004247:DNA / Q000032:analysis; D003661:Decision Support Techniques; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007155:Immunologic Factors / Q000009:adverse effects*; D018579:Patient Selection; D011247:Pregnancy; D012203:Rh Isoimmunization / Q000517:prevention & control*; D018029:Rho(D) Immune Globulin / Q000009:adverse effects*
chemical_list: D007155:Immunologic Factors; D018029:Rho(D) Immune Globulin; D004247:DNA
keywords: Cell-free DNA; Rh alloimmunization; RhIG